CCP2014: The deadline for contributed oral presentations has passed (June 15), but poster abstracts are accepted until July 31, 2014.

11-14 August 2014

US/Eastern timezone

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Displaying 281
contributions
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281

Type: Poster presentation
Track: Quantum many-body physics

We present a formalism for simulating quantum dynamics of lattice spin-one systems first introducing local hidden variables and then doing semiclassical (truncated Wigner) approximation in the extended phase space. In this way we exactly take into account the local on-site Hamiltonian and approximately treat spin-spin interactions. In particular, we represent each spin with eight classical SU(3) v
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Presented by Shainen DAVIDSON

Type: Poster presentation
Track: Quantum many-body physics

A Valence bond solid (VBS) is a kind of long-range nonmagnetic order that can appear in certain quantum spin systems. Recent innovations in models and simulation techniques have enabled large-scale numerical studies of the quantum phase transition from a power-law quasi-Neel-ordered state to the VBS-ordered state. These studies have found evidence for the fractionalization of triplons into deconfi
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Presented by Mr. Adam IAIZZI

Type: Poster presentation
Track: Classical statistical mechanics and complex systems

Complex networks have been proven to be an important tool to
study complex systems. Moreover, thestudy of interdependent substructures
of complex networks attracted much interest recently.
The k-core percolation approach is one way to identify the highly
connected sub-structures and has been extensively studied for single
networks [1]. In reality, diverse critical infrastructures are coupled
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Presented by Mr. Nagendra PANDURANGA

To find plasma facing materials (PFM), which must endure a plasma irradiation, is one of the important issues in order to realize the nuclear fusion reactor. Tungsten material is one of the candidates of PFMs. However, bubble or nano-structure formation in tungsten is observed under the irradiation of helium onto the tungsten surfaces. This structure appears not only in tungsten but also in other
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Presented by Prof. Hiroaki NAKAMURA
on
12 Aug 2014
at
17:00

Type: Poster presentation
Track: Classical statistical mechanics and complex systems

It is well known that the Vlasov-Maxwell system can be considered as an infinite dimensional Hamiltonian system, where the Hamiltonian structure is non canonical and depends on the solution itself (Poisson structure), see e.g. [1] and [2]. This is of interest, as contrary to the Vlasov-Poisson system for which the natural splitting between spatial advection and velocity advection is also a Hamilto
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Presented by Dr. Lukas EINKEMMER

For more than three decades, the instabilities caused by one
fluid invading the pore space of another in a porous medium have been studied resulting in a rich phase diagram depending on the wetting properties of the fluids with respect to the pore walls, their viscosities and the speed at which the invasion happens.
The situation when two immiscible fluids flow simultaneously in the porous me
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Presented by Prof. Alex HANSEN
on
11 Aug 2014
at
14:30

Type: Poster presentation
Track: Computational-physics education

The study of N-body dynamics is a common practice with many realistic applications and examples, yet the ability to accurately model the interactions of large, dynamic planets via computer simulation remains an area of current research.<sup>1</sup> We report the results from a parallel computational model using long-range gravitational attraction and short-range, hard-sphere Hooke’s law interac
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Presented by Mr. Samuel CASTLE

In this talk, we present parallel implementation of the Dirac equation in 1(space)+1(time) dimension using space-time finite element discretization. We show that the space-time finite element method for the time-based Dirac equation converges to analytic solutions without artificial stabilization or after-simulation tuning even in the low-mass regime. Due to the large size of the problem, using a
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Presented by Hyun LIM
on
11 Aug 2014
at
17:15

Type: Contributed talk
Session:
Astro Physics 2
Track: Astrophysics, space-plasma physics, gravitation, cosmology

For certain formulations of partial differential equations, proper time-parallel preconditioners can be successfully applied in space-time finite element simulations. Such an approach may enable the extraction of more parallelism to better utilize high performance computing resources. In this work, we examine the behavior of the semi linear wave equation in 1 + 1 dimensions using the space-time fi
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Presented by Hyun LIM
on
14 Aug 2014
at
09:45

Data Centric Systems (DCS) focus on the problem of data location, and the principle that moving computing to the data will lead to more cost effective, efficient, and easier to program systems than prior generation systems. DCS hardware, which is heterogeneous by nature, will provide leadership capabilities for Big Data, complex analytics, modeling/simulation and cognitive computing. DCS softwar
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Presented by Dr. James SEXTON
on
12 Aug 2014
at
11:15

Based on the solution of the Ornstein-Zernike Equation, we present our analytical coarse-grained model that is structural and thermodynamic consistent across multiple length scales.[1] The model in this way is fully predictive, when the potential is used as an input in mesoscale molecular dynamic simulations of polymer melts.
The model is analytical and depends on molecular and thermodynamic para
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Presented by Marina GUENZA
on
12 Aug 2014
at
13:30

The simple geometry of a polymer film on a substrate with a step at the free surface is unfavourable due to the excess interface induced by the step, thus allowing for a new nanoprobe of the melt state rheology. After describing the experimental technique [1], we demonstrate how the theoretical tools [2,3] enable to directly probe the surface evolution of thin polymer films below the glass transit
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Presented by Dr. Thomas SALEZ
on
12 Aug 2014
at
14:30

Type: Poster presentation
Track: Other areas of computational physics

Kinetic equations containing fractional derivatives are a useful approach for the description of transport in complex systems which exhibit anomalous diffusion and memory effects. It is this non-Markovian nature which results in increased computational complexity when solving these equations numerically. For an <em>N</em>-point finite difference discretisation this corresponds to accessing the ent
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Presented by Prof. Ronald WHITE

Type: Poster presentation
Track: Materials science and nano science

The accurate, fast and reliable determination of the surface area and pore volume of microporous materials is receiving great attention due to the extensive applications of such materials (e.g. zeolites, Metal-Organic Frameworks (MOFs) etc.) in highly important industrial processes (catalysis, adsorption etc.).
The most popular method for deriving the surface area of a porous solid is based on a
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Presented by Mr. Stylianos N. KAROZIS

We present a scalable algorithm for computing Rényi entanglement entropies in systems of itinerant bosons in the spatial continuum via quantum Monte Carlo. This method is applicable to the study of spatial mode entanglement, particle partitioned entanglement, and the entanglement of particles under a spatial partitioning. We demonstrate its utility by studying a non-trivial interacting Bose gas
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Presented by Prof. Adrian DEL MAESTRO
on
13 Aug 2014
at
14:45

Type: Poster presentation
Track: Fluid dynamics, magnetohydrodynamic

Flow around a solid body at high Reynolds number is often computed efficiently using inviscid vortex methods, if the distribution of vorticity shed from the surface of the body can be predicted accurately. The only method currently available for predicting the shed vorticity is by the application of the Kutta condition, which applies to slender wings at the leading and trailing edges. This limits
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Presented by Shreyas MANDRE

Type: Poster presentation
Track: Materials science and nano science

First-principles pseudopotential calculations of the lattice constants and of the single-crystal elastic constants for ternary metal nitrides TaxMo1-xN and TaxW1-xN alloys were carried out. The cubic B1-rocksalt structure is considered. These calculations were performed using density functional perturbation theory (DFPT). For the exchange-correlation potential, we used the generalized gradient met
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Presented by Dr. Khellil BOUAMAMA

Particle-in-cell (PIC) codes commonly employ a finite-element method in order to solve Vlasov's equation and a finite-difference-time-domain method to solve Maxwell's equations. The number of quasi-elements used in the finite element solver is significant for the reliability of the obtained results and a defining property when evaluating the computational demands of a given simulation. Thus its dy
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Presented by Mr. Nils MOSCHUERING
on
11 Aug 2014
at
15:00

Type: Poster presentation
Track: Materials science and nano science

Precise shaping of laser beam has recently become of great technological importance due to its possible applications in various fields of science and technology [1-2]. For instance, the use of a multi-point laser in confocal laser scanning microscopy helps to improve overall performance of the method, which is crucial for investigation of ultra-fast processes in biology. Shaping the laser beam int
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Presented by Mr. Sergei ZAKHARCHENKO

Type: Poster presentation
Track: Soft-matter, polymer, and biological physics

Fluorouracil is a modified nuclear acid and a common chemotherapuetic, yet much remains to be known about its molecular properties. We will present initial results on long-time simulations of two fluorouracil systems. The first is the polymeric form, F10, where we present initial results on various conformations that our microsecond-scale simulations have discovered. The second, will be fluorourac
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Presented by Prof. Freddie SALSBURY

Type: Poster presentation
Track: Quantum many-body physics

The interaction of a localized magnetic moment with the conduction electrons in a metallic host defines a problem with numerous facets. At sufficiently low temperatures, below the Kondo temperature $T_{K}$, this interaction gives rise to the Kondo effect and forms a spin-polarized region known as the Kondo screening cloud. Previous theories suggest that the radius of the cloud is $R_K = \hbar v_F
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Presented by Ms. Krissia de ZAWADZKI

Type: Poster presentation
Track: Astrophysics, space-plasma physics, gravitation, cosmology

The nature of the dark matter is one of the most intriguing and fundamental subjects in Modern Physics. The Scalar Field Dark Matter (SFDM) model, which assumes that dark matter is composed by bosonic particles that can be described by an scalar field, is an alternative model to the Cold Dark Matter (CDM) model and is as succesful as this one at cosmological scales, even more, the SFDM would be f
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Presented by Mr. Carlos Arturo SOTO-CAMPOS

Type: Poster presentation
Track: Computational-physics education

Radiation reaction is one of the self-field effects on electrons that become important at large radiation efficiencies of the latter. Radiation reaction is typically important when ultra-strong fields interact with electrons. With the help of mean-field transport equations for electrons and photons the Particle-In-Cell (PIC) method can be applied to integrate the radiation reaction force and to ob
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Presented by Prof. Hartmut RUHL

Cross sections of charged paricles interactions are needed in many area of physics. Knowledge of accurate elatic differential angular distributions and mean free paths of electrons with water molecule is of great importance in medical and radiation physics. These two quantities are often used as a data base in general purpose Monte Codes to model the transport of particles.The present work provide
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Presented by Dr. Zine El Abidne CHAOUI
on
12 Aug 2014
at
14:15

Compressed sensing (or compressive sampling) [1,2] is a method originally developed by the signal analysis community to minimize the data required to reconstruct a signal, based on the ideas of incoherent sampling and sparse optimization.
In this talk we will discuss our effort to apply compressed sensing and related techniques to the computational simulation of atomic systems, and we will sho
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Presented by Dr. Xavier ANDRADE
on
14 Aug 2014
at
09:45

Type: Poster presentation
Track: Materials science and nano science

There is an increasing demand to model the structural evolution of Li-containing Si electrodes, because this is an attractive candidate for the anode of Li-ion batteries. Investigating structural phenomena such as phase transitions and nano-scale dynamics of the Li-Si systems are inaccessible by first-principles approaches because realistic simulations require large numbers of atoms and long time
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Presented by Berk ONAT

Type: Contributed talk
Session:
Statistical Mechanics: Networks
Track: Classical statistical mechanics and complex systems

The so-called "Yard-Sale Model" of wealth distribution posits that wealth is transferred between economic agents as a result of transactions whose size is proportional to the wealth of the less wealthy agent. In recent work [1,2], we have shown that this model results in a Fokker-Planck equation governing the wealth distribution of the population. In the absence of any mechanism for wealth redis
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Presented by Prof. Bruce BOGHOSIAN
on
11 Aug 2014
at
17:15

Type: Poster presentation
Track: Materials science and nano science

A variety of pump-probe experiments are emerging to monitor the ultrafast structural response of materials. Typically a hot electron distribution is generated by an ultrafast laser pulse or by high energy particle beams, such as swift heavy ions. The hot electron distribution then thermalizes relatively quickly, on timescales in the 100fs range, while the lattice response is slower. Structural pro
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Presented by XUKUN XIANG

Modern HPC applications employ increasingly advanced discretisation methods to study multi-physics problems. Modern HPC architectures consist of heterogeneous multi-core many-node systems with deep memory hierarchies. Developing applications that are able to explore cutting-edge physics on cutting-edge HPC systems has become a complex task that requires significant HPC knowledge and experience, wh
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Presented by Erik SCHNETTER
on
12 Aug 2014
at
16:15

Type: Contributed talk
Session:
Statistical Mechanics: Networks
Track: Classical statistical mechanics and complex systems

A Monte-Carlo algorithm for discrete statistical models that combines the full power of the Belief Propagation algorithm with the advantages of a detailed-balanced heat bath approach is presented. A sub-tree inside the factor graph is first extracted randomly; Belief Propagation is then used as a perfect sampler to generate a configuration on the tree given the boundary conditions and the procedur
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Presented by Prof. Florent KRZAKALA
on
11 Aug 2014
at
16:45

Statistical learning of materials properties or functions so far starts with a largely silent, non-challenged step: the introduction of a descriptor. However, when the scientific connection between the descriptor and the actuating mechanisms is unclear, causality of the learned descriptor-property relation is uncertain.
Thus, trustful prediction of new promising materials, identification of anom
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Presented by Dr. Luca GHIRINGHELLI
on
11 Aug 2014
at
13:30

Type: Poster presentation
Track: Fluid dynamics, magnetohydrodynamic

Hydrogen is a very promising alternative fuel which is expected to play a significant role in the near future. Hydrogen is considered as an excellent alternative fuel due its potential to lead to significant reductions in greenhouse gas emissions and significant improvements in energy efficiency. On the other hand, significant safety issues are associated with it. In the case of an accidental rele
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Presented by Mr. ILIAS TOLIAS

In studies of epitaxial growth, analysis of the distribution of the areas of capture zones (i.e. proximity polygons or Voronoi tessellations with respect to island centers) is often the best way to extract the critical nucleus size <em>i</em> (the largest island size that can decay). For non-Poisson deposition (i.e. when island nucleation is not fully random), the normalized areas <em>s</em> of th
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Presented by Prof. Theodore L EINSTEIN
on
11 Aug 2014
at
14:45

Type: Poster presentation
Track: Materials science and nano science

On account of their diverse and fascinating applications in wide technological and scientific fields, the synthesis and characterization of nano-sized magnetic materials have emerged as an important subject during last several years. Among these, ferrites, ferromagnetic having cubic spinel structure (MFe<sub>2</sub>2O<sub>4</sub>) are complex versatile materials have been extensively investigated
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Presented by Mrs. Rabab ZAHIRA

The Haldane Insulator (HI) is a gapped phase characterized by an
exotic non-local string order parameter. The parameter regimes at
which it might exist, and how it competes with alternate types of
order, such as supersolid (SS) order, are still incompletely
understood. Using the Stochastic Green Function quantum Monte Carlo
and the Density Matrix Renormalization Group, we study for a wide
r
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Presented by Prof. George BATROUNI
on
11 Aug 2014
at
14:30

The rheological behavior of complex fluids under shear exhibits many interesting features arising from the strong coupling between mesoscopic structure and flow. Complex temporal response indicating the occurrence of deterministic chaos has been observed in experiments on sheared wormlike micelles [1]. The chaotic behavior in this system, known as "rheochaos", occurs at very small values of the Re
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Presented by Prof. Chandan DASGUPTA
on
11 Aug 2014
at
14:45

Theoretical model for calculating the thermodynamic properties of nano-porous materials with weak guest-host interactions was proposed for gas storage/separation applications. The proposed model accounted for multiple cage occupancy, host lattice relaxation, and the description of the quantum nature of guest behavior [1]. Using this approach, the phase diagrams of the pure and clathrate hydrates [
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Presented by Prof. Rodion BELOSLUDOV
on
13 Aug 2014
at
14:00

The process of constructing and exploring computational models can offer significant support for the development of conceptual understanding of key ideas in physics. However, most students in the U.S. who take introductory physics courses in university have had no prior exposure to programming. By selecting a minimal set of computational concepts to teach, and by introducing these concepts in the
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Presented by Ruth CHABAY
on
12 Aug 2014
at
15:45

Type: Poster presentation
Track: Materials science and nano science

Recently many researchers have used DNA as a scaffold for the accurate placement of molecules and for the design of arbitrary supramolecular structures. Functional mechanical devices have even been designed and synthesized. The specificity, addressability, and predictability of DNA structures allow for the placement of light-absorbing dyes in arbitrary patterns with sub-nanometer precision. In the
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Presented by Nicolas SAWAYA

Type: Poster presentation
Track: Fluid dynamics, magnetohydrodynamic

This study presents the computational fluid dynamics simulations of the boundary layer control by modifying the blade geometry of a Darrieus Turbine blade for use in wind energy conversion following the tubercule geometry of a humpback whale. The blade is designed for a constant cross section H-type Darrieus turbine. Finite-volume based software ANSYS Fluent was used in the simulations. Using the
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Presented by Prof. AYDOGAN OZDAMAR

Transition-metal alloyed nanoparticles (NPs) are key components in current and emerging energy technologies because they are found to improve catalytic activity and selectivity for many energy-conversion processes. However, the difficulty of characterizing and describing the structural and compositional changes in alloyed NPs under reactive conditions remains a significant challenge. To address th
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Presented by Lin-Lin WANG
on
11 Aug 2014
at
14:00

The future of high performance computing is jeopardized by the end of Dennard scaling and the approaching end of Moore’s Law, eliminating the two principal sources of exponential performance gain that has dominated the field for more than two decades. Future science applications demand increased fidelity, physics phenomenology, multi-scale formulation, efficiency, and scalability. It is further
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Presented by Dr. Sterling THOMAS
on
12 Aug 2014
at
10:30

The dominant hypothesis in amyloid diseases considers small amyloid aggregates as one of most important toxic species. Because these structures are out-of-equilibrium, there atomistic properties are difficult to access experimentally. Computer simulations have therefore played an important role for their characterization over the last decade. Yet, full size amyloid aggregates are at the extreme l
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Presented by Prof. Normand MOUSSEAU
on
11 Aug 2014
at
16:15

Type: Poster presentation
Track: Computational-physics education

In computational physics we often need to solve problems
expressed in partial differential equations, such as the
Laplace and Schroedinger equations. One approach involves
discretizing space into regular grids, or meshes, over which the
differential operators are approximated.
There is another class of meshfree methods. In the meshfree approach,
rather than discretizing space, the solutio
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Presented by Dr. Jay WANG

The ideal structure of graphene can be disrupted by various ways, such as by the producing the vacancies and by the replacement of carbon atoms with other atoms, in particular, with nitrogen or silicon atoms [1]. In our work, the structural changes of a rectangular nanographene ribbon consisting of 272 atoms as a result of its interaction with ringlike carbon clusters have been studied.
Using the
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Presented by Mr. Abdiravuf DZHURAKHALOV
on
12 Aug 2014
at
17:15

Type: Poster presentation
Track: Other areas of computational physics

It is shown that the usual model for confined one-centre systems can be extended to two-centre systems and the theory is used to treat H<sub>2</sub> and HeH<sub>++</sub> . It is convenient to use spheroidal coordinates for the two-centre problems and we use this formalism to compare hydrogen-like systems confined spheroidally with the more standard spherical confinement. A discussion of confin
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Presented by Prof. Brian BURROWS

Type: Invited talk
Session:
Lattice Gauge Theory 2
Track: Lattice field theory in particle and nuclear physics

Fluctuations of conserved charges, i.e. baryon number, strangeness and electric charge, are sensitive probes for the transition from the confined hadronic to the deconfined partonic phase of strong interaction matter. Rapid changes of, e.g. quadratic fluctuations of net baryon number, net strangeness as well as correlations between these conserved charges, signal the change of degrees of freedom t
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Presented by Prof. Frithjof KARSCH
on
12 Aug 2014
at
16:15

Type: Poster presentation
Track: Soft-matter, polymer, and biological physics

Morphogenesis, spontaneous formation of organism structure, is essential in life. In pancreas, endocrine alpha, beta, and delta cells are clustered to form islets of Langerhans, the critical micro-organ for glucose homeostasis. The spatial organization of endocrine cells in islets looks different between species. Based on the three-dimensional positions of individual cells in islets, we computatio
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Presented by Mr. Danh-Tai HOANG

Because of their scale invariant nature, critical systems in two dimensions can harbor universal terms in their entanglement entropy depending on the geometry of the cut between the entangled subsystems. For certain special systems, the coefficient of a term associated with a sharp corner geometry has been found to roughly count the number of bosonic fields, similar to the central charge of a 1+1
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Presented by Dr. Edwin STOUDENMIRE
on
13 Aug 2014
at
15:00

Titin kinase is a mechanoenzyme, whose activity is activated by mechanical stretching and binding of calcium sensors. Stretching causes local and global conformational changes of secondary structures and complex movements of ion pairs and transient formations of salt bridges. This paper applies the adaptive time series analysis approach to study the mechanical responses of ion-pair movements to st
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Presented by Dr. Ming-Chya WU
on
11 Aug 2014
at
16:45

Type: Contributed talk
Session:
Astro Physics 1
Track: Astrophysics, space-plasma physics, gravitation, cosmology

We present the cosmological simulations of impact of the first binaries. Recent studies of the first star formation suggest that those stars tend to form into binaries or multiple stellar systems instead of single stars, so the first stars could be less massive than we originally thought. It implies the first stars would die as score collapse supernovae instead of pair-instability supernovae, both
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Presented by Dr. Ke-Jung CHEN
on
13 Aug 2014
at
15:00

The superfluid-insulator quantum phase transition that takes place in disordered bosonic system instigate many discussions and controversies since its first studies more than 20 years ago [1]. The understanding of this transition is relevant to various systems, to cite a few, <sup>4</sup>He in porous media, thin superconducting films and cold atoms in disordered optical lattice [2,3]. Though many
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Presented by Ms. Karine PIACENTINI COELHO DA COSTA
on
11 Aug 2014
at
14:45

Type: Invited talk
Session:
Lattice Gauge Theory 3
Track: Lattice field theory in particle and nuclear physics

We consider two-colour QCD with two flavours of quarks as a possible theory of composite dark matter and use lattice field theory methods to investigate nuclear spectroscopy in the spin J=0 and J=1 multi-baryon sectors. We find compelling evidence that J=1 systems with baryon number B=2,3 (and their mixed meson-baryon counterparts) are bound states - the analogues of nuclei in this theory. We disc
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Presented by Dr. William DETMOLD
on
14 Aug 2014
at
09:00

Type: Poster presentation
Track: Novel hardware and software paradigms

Physics applications consume considerable portion of supercomputing resources. As computers grow in capabilities, programming complexity grows as well. Complexity of programing large computing clusters needs to be addressed. Qlua is a revival of the data parallel programming paradigm based on a popular programming language Lua. The current implementation is tailored to Lattice QCD needs with dom
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Presented by Dr. Andrew POCHINSKY

Close to the absolute zero of temperature, when pushed to the edge between two phases of matter, simple lattice Hamiltonians of spins can display the incredibly rich phenomena of "quantum criticality". Quantum critical ground states are described by the most complex wavefunctions known to physicists, yet they can be categorized by "universality classes" that are independent of the details of the H
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Presented by Prof. Ribhu KAUL
on
11 Aug 2014
at
13:30

Type: Poster presentation
Track: Fluid dynamics, magnetohydrodynamic

Number of vortices in an evaporating droplet essentially depend on the thermal conductivity and the thickness of the substrate, on the contact angle and on the parameters of the fluid. In this work we perform detailed numerical calculations of the effect and find the temperature distribution and vortex structure in a droplet. We present "phase diagrams", which contain information on the number, or
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Presented by Dr. Lev BARASH

Density functional theory (DFT) calculations suggest that polymers having tin atoms in their backbones may have high dielectric constants [1,2]. A class of organotin polymers, called tin esters, were then synthesized, realizing this prediction [3,4]. Motivated by this result, we developed a high-throughput screening scheme to quickly predict the desired performances for an energy storing dielectri
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Presented by Dr. Tran HUAN
on
13 Aug 2014
at
14:30

Type: Poster presentation
Track: Materials science and nano science

Nanostructured materials are of major interest in many sectors such as environment, energy and biosciences as they find numerous applications (e.g. as carriers, sorbents, composites etc.) in processes of high industrial significance. On the molecular level, the determination of partial charges on such materials is necessary for the estimation and explanation of their unique properties. In the pres
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Presented by Dr. George P. LITHOXOOS

We have developed computational approaches to examine ground state properties, excitations and nonequilibrium response of strongly correlated nanostructures. The algorithm is based on merging Dynamical Mean-Field Theory (DMFT) with both Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TDDFT). The DMFT approach has already been established as a reliable tool to study co
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Presented by Dr. Volodymyr TURKOWSKI
on
13 Aug 2014
at
15:45

Type: Poster presentation
Track: Materials science and nano science

The real-space approach is widely used for electronic structure calculations based on density functional theory [1]. In particular, it is used for large systems that include many atoms, because a real-space mesh is suitable for large-scale parallel computing. The real-space approach also allows the capture of a clear physical image because it does not use an explicit basis such as a plane wave or
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Presented by Prof. Yasunari ZEMPO

Electronic structure determination is the first step towards theoretical modeling of optical properties such as absorption and emission spectra of low dimensional semiconductor. A possible theoretical approach for these band structure calculations is the k.p method in reciprocal space [1], a perturbative model that describe the energy bands around a high symmetry point. In the case of quantum conf
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Presented by Mr. Tiago DE CAMPOS
on
14 Aug 2014
at
09:15

Under certain (controlled) conditions, Feynman diagrammatic series for fermionic systems features the phenomenon of sign blessing: The series converges despite factorial growth of the number of diagrams with diagram order. Diagrammatic Monte Carlo technique allows us to sample millions of Feynman diagrams. With the universal fermionization trick, we can fermionize essentially any (bosonic, spin, m
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Presented by Prof. Boris SVISTUNOV
on
11 Aug 2014
at
14:00

Type: Poster presentation
Track: Quantum many-body physics

We present recent advances in the study of the evolution from the weak-coupling semimetal into the strong-coupling, insulating regime by means of unbiased quantum Monte Carlo simulations of the Hubbard and related models on the honeycomb lattice at half filling. Employing a novel approach to quantum phase transitions, we perform non-equilibrium imaginary time quenches of the Hubbard model in (zero
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Presented by Dr. Thomas C. LANG

Type: Poster presentation
Track: Classical statistical mechanics and complex systems

We consider non-equilibrium dynamics of systems driven out of equilibrium at
some finite rate near phase transitions. In previous work [1] on systems
with varying temperature, scaling behaviors have been tested in great
detail. Here with Monte Carlo simulations, we investigate the 2D Ising Model
with linearly varying magnetic field and demonstrate the applicability of
similar scaling function
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Presented by Na XU

Type: Poster presentation
Track: Soft-matter, polymer, and biological physics

We investigated the influence of surface attractive strength on structural transitions of a hydrophobic-polar (HP) lattice protein model [1] confined between two parallel attractive walls. Thermodynamics and structural properties have been determined by employing Wang-Landau sampling [2, 3] together with efficient Monte Carlo updates (pull moves [4] and bond-rebridging moves [5]). The simulations
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Presented by Ms. Busara PATTANASIRI

We investigate the transient states in nonequilibruim time-dependent systems. Intense ultrafast laser pulses allow the preparation of transient states of matter exhibiting strong non-equilibrium between electrons and lattice. By controling the laser pulse, we are able to change the transient states of these quantum systems. The optical and structural properties as well as the temporal evolution of
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Presented by Mr. Bin HWANG
on
13 Aug 2014
at
17:15

Effects of Strain on Electronic Transport Property of Graphene Nanoribbons between metallic contacts

Type: Poster presentation
Track: Materials science and nano science

Strain in graphene is very common as graphene samples are integrated to substrate and it can affect the electronic structure and transport properties of graphene. In a sample of graphene from chemical vapor deposition, the resistance remains around 7.5ΚΩ under less than 3% strain, while sharply enhances to 25ΚΩ under 5% strain [1]. Based on enhancement in the resistance by strain, graphene-bas
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Presented by Dr. Guiping ZHANG

The effects of metallic contacts on electronic transport of graphene had not been completely estimated however widely discussed[1-3], hence we propose two powerful methods, i.e., exact [4] and renormalized transfer matrix method [5,6]. On one hand, results from exact transfer-matrix methods are valid for all sheet widths and lengths. In the limit of the large width-to-length ratio relevant to rece
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Presented by Dr. GUIPING ZHANG
on
12 Aug 2014
at
14:00

Type: Poster presentation
Track: Classical statistical mechanics and complex systems

Spin glasses are the archetypal benchmark problem when developing and
characterizing optimization algorithms. In particular, the recent
development of quantum annealing machines has increased the demand for
ground-state test instances on (quasi) two-dimensional lattices. The
scaling with the number of spins (i.e., size of the input) when
determining the minimum of a spin-glass Hamiltonian (i
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Presented by Zheng ZHU, Andrew OCHOA

Since single mirror telescopes are heavy and difficult to manufacture and install, segmented, multiple mirror systems have become popular. Such systems are analogous to surfaces of Solid-on Solid (SOS) models, with similar Hamiltonians, although the SOS system energy has to be minimiized and the image quality maximized. Both systems have multiple valleys (peaks) in their phase space. Experience wi
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Presented by Dr. Joan ADLER
on
12 Aug 2014
at
15:00

Type: Poster presentation
Track: Materials science and nano science

Nowadays second harmonic generation (SHG) is widely used in order to extend spectral range of conventional laser sources. SHG efficiency depends on phase velocities of interacting waves. Refractive index of the crystal depends on its temperature. Crystal 3D temperature distribution is crucial [1,2]. For measurement of thermodynamic temperature of laser heated crystal we have introduced the concept
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Presented by Mr. Andrey BARANOV

Type: Poster presentation
Track: Computational-physics education

Nowadays, the teaching in computational physics is based on the usage of powerful instructional tools (e.g. Mathematica) and the programming in several software languages (e.g. Java) to do algebraic and numerical calculations, graphics and animations for a variety of mathematics and physics problems. However, the deployment of these animations requires that the author have training and skills in
... More

Presented by Prof. Felix J. GARCIA-CLEMENTE

Type: Contributed talk
Session:
Lattice Gauge Theory 1
Track: Lattice field theory in particle and nuclear physics

For some time, the MILC Collaboration has been studying electromagnetic effects on light mesons. These calculations use fully dynamical QCD, but only quenched photons. That is, the sea quarks are electrically neutral, while the valence quarks carry charge. The photons are quenched and use the non-compact formalism. We have new results with lattice spacing as small as 0.045 fm. In addition, we
... More

Presented by Prof. Steven GOTTLIEB
on
12 Aug 2014
at
14:30

Green sulfur bacteria are an iconic example of nature’s adaptation: thriving in environments of extremely low photon density, the bacterium ranks itself among the most efficient natural light-harvesting organisms. The photosynthetic antenna complex of this bacterium is a self-assembled nanostructure, ≈60 × 150 nm, made of bacteriochlorophyll molecules. In this talk, I will discuss our recent
... More

Presented by Stephanie VALLEAU
on
13 Aug 2014
at
14:15

Type: Poster presentation
Track: Materials science and nano science

Electronic Properties of Trimesic Acid Layers Adsorbed on Graphene
F. Shayeganfar1, A. Rochefort1
1Engineering Physics Department and Regroupement sur les matériaux de pointe
(RQMP), École Polytechnique de Montréal, Canada
Abstract
In order to study the effect of adsorbed molecules on the electronic structure of graphene,
trimesic acid (TMA) in an isolated form, or within a hy
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Presented by Dr. farzaneh SHAYEGANFAR

Type: Poster presentation
Track: Materials science and nano science

The softening in elastic constants of the silicon has attracted much attention because the density of silicon vacancies can be evaluated from it[1]. It is also reported that the elastic softening is suppressed by an external magnetic field in the boron-doped silicon[1]. Several papers concerning such phenomena have been published so far, and it is pointed out that the spin-orbit interaction play
... More

Presented by Prof. Katsuhiko HIGUCHI

Improving the accuracy of the results and the quality of predictions is one of the major challenges in atomistic simulation of condensed matter. The solution is thought to lie in developing a multiscale approach that would seamlessly integrate quantum and classical dynamics and the early work in this field has been recognised by the 2013 Nobel Prize in Chemistry. The now standard methods are almos
... More

Presented by Dr. Vlad SOKHAN
on
11 Aug 2014
at
15:00

Type: Poster presentation
Track: Soft-matter, polymer, and biological physics

We study the structural features and underlying principles of multi-dislocation ground states of a crystalline spherical cap. In the continuum limit where the ratio of crystal size to lattice spacing <em>W/a</em> diverges, dislocations proliferate and ground states approach a characteristic sequence of structures composed of radial grain boundaries (``neutral scars"), extending radially from the
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Presented by Mr. Amir AZADI

Type: Plenary talk
Track: CCP2014 plenary sessions

This talk will highlight enabling technology trends in high performance computing, including hardware and software perspectives for current and future generation systems on the path to exascale. As we know, the total power budget that can realistically be deployed for future exascale systems requires energy-efficient innovations to be made across all facets of supercomputing
design ranging from o
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Presented by Dr. Karl SCHULZ

Complex fluids is ubiquitous in our daily life, from the food we eat, the things we use to the exact materials we are made of. It is also important in many industrial, physical and biological applications. Studying these materials requires a wide range of tools and techniques for different disciplinary, even within mathematics.
It is the competitions and couplings of different physics from mult
... More

Presented by Prof. Chun LIU
on
11 Aug 2014
at
16:15

Conventional Monte Calro and molecular dynamics simulations of spin and biological systems are greatly hampered by the multiple-minima problem, where the simulations tend to get trapped in some of a huge number of local-minimum-energy states which are separated by high energy barriers. In order to overcome this difficulty, we have been advocating the uses of generalized-ensemble algorithms which a
... More

Presented by Prof. Yuko OKAMOTO
on
11 Aug 2014
at
10:30

Type: Poster presentation
Track: Quantum many-body physics

We present a numerical scheme to reconstruct a subset of the entanglement spectrum of quantum many body systems using quantum Monte Carlo. The approach builds on the replica trick to evaluate particle number resolved traces of the first n of powers of a reduced density matrix. From this information we reconstruct n
entanglement spectrum levels using a polynomial root solver. We illustrate the pow
... More

Presented by Mr. Chia-Min CHUNG

Type: Poster presentation
Track: Quantum many-body physics

Results for the 2D tJ entropy at J/t=0.4 for all temperatures T and electron densities n are reported, along with a comparison to the properties of the thermopower in cuprate superconductors. The calculation is done by combining data from Monte Carlo calculations for the 2D Heisenberg AF energy as a function of T [1] with high temperature series calculated to 12th order in 1/T for the tJ entropy.
... More

Presented by Prof. William PUTIKKA

Type: Poster presentation
Track: Classical statistical mechanics and complex systems

We investigate the Fokker-Planck description of the equal-time probability distribution function (PDF) of the three-dimensional Lorenz-63 attractor [1] modified with the addition of stochastic forcing. The steady-state PDF is found by time-evolving an initial PDF forward in time under the action of the linear Fokker-Planck operator. The PDF is compared to that obtained by the traditional method o
... More

Presented by Mr. Altan ALLAWALA

Type: Invited talk
Session:
Statistical Mechanics: Spin Models 2
Track: Classical statistical mechanics and complex systems

Mean-field theory of spin glasses has provided a number of novel concepts for understanding of a phase transition in disordered glassy systems. In particular, replica-symmetry breaking (RSB) plays an essential role in describing complex free-energy structure. It turns out that the pattern of RSB is clarified into two distinct classes, full RSB and one-step RSB. Despite extensive studies including
... More

Presented by Dr. Koji HUKUSHIMA
on
13 Aug 2014
at
13:30

Type: Poster presentation
Track: Astrophysics, space-plasma physics, gravitation, cosmology

The geomagnetic storm represents the most outstanding example of solar wind- magnetospheric interaction, which causes global disturbances in the geomagnetic field as well as the trigger ionospheric disturbances. We study the behaviour of ionospheric Total Electron Content (TEC) during the geomagnetic storms. For the present investigation we have selected 47 intense geomagnetic storms (Dst ≤ -100
... More

Presented by Dr. Pramod Kumar PUROHIT

Type: Poster presentation
Track: Materials science and nano science

Clathrate hydrates are crystalline materials made of water molecules. Their crystal lattice consists of cavities where gas molecules can be entrapped. As such, they have attracted extensive interest as potential materials for the storage of energy-related gases (e.g. hydrogen, methane, carbon dioxide).
We have used Monte Carlo simulations to examine the efficiency of several hydrate structures in
... More

Presented by Dr. Nikolaos PAPADIMITRIOU

1T-TaS<sub>2</sub> is a transition-metal layered compound that shows unique electronic properties, resulting from a variety of temperature dependent phases with different structures. ForT<190K, this material displays a commensurate charge density wave (C-CDW) phase characterized by insulating behavior corresponding to the opening of a gap at the Fermi energy. To better understand the C-CDW phase
... More

Presented by Jenni PORTMAN
on
12 Aug 2014
at
16:45

Type: Poster presentation
Track: Materials science and nano science

The semi-classical mapping of the second-quantized many-electron Hamiltonian proposed by Miller and coworkers [1,3] is being merged with the Partial Linearized Density Matrix (PLDM) scheme [2], a quantum dynamical method for the evolution of the density matrix. The combination of the two approaches will allow us to accurately describe electron correlations through real time dynamics. This new appr
... More

Presented by Mr. Angelo ZILETTI

Quantum annealing is an optimization method designed to take advantage
of quantum phenomena, such as quantum superposition, tunneling and
quantum fluctuations. Diabatic transactions between energy levels, and
thermal excitations and relaxation, can play an important role in
quantum annealing (as opposed to adiabatic quantum computation). DWave
has implemented a physical quantum annealing prot
... More

Presented by Dr. Boixo SERGIO
on
13 Aug 2014
at
16:45

Type: Contributed talk
Session:
Statistical Mechanics: Spin Models 2
Track: Classical statistical mechanics and complex systems

The Wang-Landau (WL) Monte Carlo method [1] has the property of generating a flat histogram in some random walk space, where the parameters for the random walk and the flatness criterion can be chosen according to the system of interest. Due to these characteristics and to the simplicity of the algorithm, the WL approach has been applied to different kinds of systems [2-5], including those with ro
... More

Presented by Ms. Alexandra VALENTIM
on
13 Aug 2014
at
14:45

Motivation is a powerful tool to help students learn. And being able to simulate Physics phenomena on tablets can be a great motivation for Computational Physics students. We introduce a major version of the successful Easy Java/Javascript Simulations (EjsS) modeling tool (http://www.um.es/fem/EjsWiki) that allows Physics teachers and students to create, share, and distribute Java and Javascript s
... More

Presented by Prof. Francisco ESQUEMBRE
on
12 Aug 2014
at
16:15

Type: Poster presentation
Track: Quantum many-body physics

We have studied the impact of non-local electronic correlations at all length scales on the Mott-Hubbard metal-insulator transition in the unfrustrated two-dimensional Hubbard model. Combining dynamical vertex approximation, lattice quantum Monte-Carlo and variational cluster approximation, we demonstrate that scattering at long-range fluctuations, i.e., Slater-like paramagnons, opens a spectral g
... More

Presented by Prof. Nils BLüMER

During the last two decades, supercomputers have grown rapidly in performance at the cost of a similar growth in power consumption. However, nowadays the computer's performance is limited by power consumption and power density, so new developed platforms have to be based on the power efficiency.
The Mont-Blanc project [1] appeared with the aim to design computer architectures capable of deliverin
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Presented by Mr. Xavier SáEZ
on
12 Aug 2014
at
16:45

The reflectivity of shocked xenon was measured in the unique experiments of Mintsev and Zaporoghets in 1989 for wavelength &lambda = 1064nm [1] and further for 694nm and 532nm [2]. There is no theoretical explanation of these results in frames of the standard methods of nonideal plasma theory. In [3] it was shown that the Drude model, with collisional frequency in Born approximation, gives reflect
... More

Presented by Dr. Ilnur SAITOV
on
13 Aug 2014
at
15:00

Spin glasses are archetypal model systems used to investigate the effects of frustration and disorder. Concepts from the study of spin glasses have been applied to fields as diverse as structural biology, geology, computer science and financial analysis. Thus, understanding these systems on a fundamental level is of paramount importance. Despite ongoing research spanning several decades, there re
... More

Presented by Dr. Helmut KATZGRABER
on
13 Aug 2014
at
08:30

Type: Poster presentation
Track: Soft-matter, polymer, and biological physics

Phosphatidylethanolamine (PE) lipid is a fusogenic lipid, encouraging the membrane fusion when incorporated into a lipid membrane. The propensity to a fusion should be measured as a decrease of free energy barrier to the membrane fusion in a molecular dynamics simulation. In order to calculate the free energy along a fusion process, we need to control the membrane morphology along a plausible fusi
... More

Presented by Dr. Shuhei KAWAMOTO

In the past few years, several methods targeting the computation of the Landau free energy using non-equilibrium dynamics have become popular. These methods introduce a time-dependent potential to bias the original potential energy. In the long time limit, the biasing force is expected to compensate for the free energy gradient, so that the biasing potential eventually reproduces the free energy s
... More

Presented by Prof. Celeste SAGUI
on
12 Aug 2014
at
14:00

Time-dependent (TD) density functional theory (DFT) is doing remarkably well in capturing the strongly bound excitons of isolated systems, even with the most simple exchange-correlation kernels, like the TD local density approximation (LDA). Though, due to a spurious long-range behavior, TD-LDA is known to fail in describing bound excitons in solids. Aiming at understanding when and why TD-DFT can
... More

Presented by Dr. Caterina COCCHI
on
13 Aug 2014
at
13:30

Type: Poster presentation
Track: Lattice field theory in particle and nuclear physics

Computing, from first principles, the hadron masses to percent accuracy [1], is only possible through simulations of Lattice Quantum Chromodynamics (QCD). With the advent of the present class of Pflop Machines and novel simulation algorithms, we now can proceed to compute per-mille effects in the particle spectrum, i.e. the proton-neutron mass difference. This difference is due to a subtle cancell
... More

Presented by Dr. Stefan KRIEG

Type: Poster presentation
Track: Classical statistical mechanics and complex systems

An optimization function of simulated annealing (SA) [1] is reexamined in the solution process for the random traveling salesman problems [2-4]. A functional defect is revealed by applying a computational physics approach, the mapping-onto-minima approach [5] (see also [3,4]) used for studies on liquid and glass: the functionality limit beyond which the method is defeated by a simple local search
... More

Presented by Dr. Manabu HASEGAWA

Large-scale problems in scientific simulation and data analysis lead to high computational costs in both spatial and temporal dimensions. There is an increasing demand of new mathematical algorithms scalable on modern supercomputing architectures for this growing complexity. However, the global nature in space and the sequential nature in time pose a great challenge for the parallelization of rela
... More

Presented by Dr. Feng CHEN
on
13 Aug 2014
at
16:45

In this talk, we discuss recent progress in the use of the GW approach and its extensions to compute electronic excitations and related spectroscopic properties of materials and nanostructures. This interacting-electron Green’s approach incorporates many-electron interaction effects through the screened Coulomb interaction W. Inclusion of electron-hole interactions (excitonic effects) within t
... More

Presented by Prof. Steven G LOUIE
on
14 Aug 2014
at
10:30

Type: Poster presentation
Track: Quantum many-body physics

We have developed a precise gap estimation method by the worldline quantum Monte Carlo method and applied the spectral analysis to the bilayer Heisenberg model and the two-dimensional <em>J</em>-<em>Q</em> model with the 4-spin interaction. The moment method for the excitation-gap estimation using the Fourier-transformed imaginary-time correlation is generalized to an asymptotically unbiased gap e
... More

Presented by Dr. Hidemaro SUWA

Type: Contributed talk
Session:
Statistical Mechanics: Spin Models 1
Track: Classical statistical mechanics and complex systems

We would like to present results from applying generalized ensemble method to studies of systems with strong first order transition such as water and methane clathrate. We present statistical temperature, entropy and free energy functions calculated for the systems under different pressures, as well as changes in structures associated with the phase transition process.
In systems with strong fi
... More

Presented by Dr. Edyta MALOLEPSZA
on
12 Aug 2014
at
17:00

"Grand canonical numerical analysis" is a technique we recently developed for quantum many-body systems to efficiently obtain the bulk physical quantities without employing a finite size scaling[1,2].
Its procedure is simple enough; preparing an open system typically of length <em>L</em>>10,
and by systematically scaling down the Hamiltonian from center toward both ends,
one could endow the
... More

Presented by Prof. Chisa HOTTA
on
13 Aug 2014
at
14:30

Graphite is the most refractory single element solid. Despite its abundance and importance the graphite melting temperature T<sub>m</sub> remains a subject of controversy. The variation of the experimentally measured T<sub>m</sub> values is more than 1000K [1,2]. The T<sub>m</sub> values tend to group in the low temperature and high temperature sets [3]. The pressure dependence of the graphite me
... More

Presented by Dr. Vladimir STEGAILOV
on
12 Aug 2014
at
16:30

Type: Poster presentation
Track: Novel hardware and software paradigms

Tracking huge number of charged particles in linear accelerator is important for high current linear accelerator’s design and optimization. In this paper, a 3D heterogeneous parallel beam dynamic simulation software LOCUS3DG is introduced. It uses CPU as well as GPU on heterogeneous computers. It is designed to simulate the beam dynamics in high current linear accelerator by tracking billions of
... More

Presented by Mr. Kewei DU

Heterogeneous computing promises more compute power while consuming less
energy. However employing GPUs and Xeon Phi’s come with a hefty price
tag. Only software that is highly adapted to these new architectures
will gain any performance increase. In my talk I will address these
questions:
* What is heterogeneous computing?
* How can it help producing better results faster?
* Is it worthw
... More

Presented by Dr. Lars KOESTERKE
on
13 Aug 2014
at
16:15

Type: Poster presentation
Track: Materials science and nano science

MnBi has the unique property of increasing coercivity with increasing temperature. As such, MnBi is potentially an excellent material for a permanent magnet up to ~200 C. To explore if we can improve its magnetic properties and stability, we use density functional theory (DFT) calculations to explore the effects of doping on MnBi properties with transition metals (TM). We have studied three types
... More

Presented by Lin-Lin WANG

Type: Poster presentation
Track: Materials science and nano science

Graphene’s exceptional mechanical properties have been exploited for various structural applications. However, graphene is also known to be brittle, with experimentally measured tensile fracture strains that do not exceed a few percent. Using classical molecular dynamics simulations, we introduce the notion of graphene “kirigami,” which can dramatically enhance the ductility of graphene. Whe
... More

Presented by Mr. Zenan QI

Type: Poster presentation
Track: Soft-matter, polymer, and biological physics

For the estimation of transition points of finite elastic, flexible polymers with chain lengths from 13 to 309 monomers, we compare systematically transition temperatures obtained by the Fisher partition function zeros approach with recent results from microcanonical inflection-point analysis. These methods rely on accurate numerical estimates of the density of states, which have been obtained by
... More

Presented by Dr. Julio ROCHA

Type: Poster presentation
Track: Quantum many-body physics

We demonstrate the application of a quantum Monte Carlo algorithm that carries out finite-velocity quenching in the imaginary time direction to approach the phase transition point. The algorithm has been established and well tested on quantum Ising models Refs. [1,2] along with a generalized scaling that is based on Kibble-Zurek mechanism Ref.[3].
We first make a distinction between the imagi
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Presented by Mr. Cheng-Wei LIU

Type: Poster presentation
Track: Novel hardware and software paradigms

GPU programming plays an important role nowadays in scientific computation. In light of past successes building accelerated algorithms using Nvidia Cuda, we use GPU to accelerate tensor network based numerical methods. We develop a general purpose tensor network library called "the Universal Tensor Network Library", Uni10. In addition to its elegant user interface, applications on uni10 can be ea
... More

Presented by Mr. Yun-Da HSIEH

Type: Poster presentation
Track: Soft-matter, polymer, and biological physics

In this work a methodology is developed for performing the geometry optimization in the free energy surface of molecular systems surrounded by complex environments like the protein cavities and solvents. This methodology is based on the idea of Nagaoka et al. [1] and allows determining the gradient and Hessian of a hybrid QM/MM Hamiltonian [2] of a molecular system embedded in an average external
... More

Presented by Dr. Yoelvis OROZCO-GONZALEZ

We present an implicit-solvent model for protein-surface interactions. Applying the theory of electrostatics in a domain divided into solvent and protein dielectric regions leads to a coupled system of PDEs. The Poisson-Boltzmann equation applies in the solvent region (water with salt), the Poisson equation with point charges in the protein region, and interface conditions at the solvent-excluded
... More

Presented by Mr. Christopher COOPER
on
14 Aug 2014
at
10:00

Type: Poster presentation
Track: Soft-matter, polymer, and biological physics

We are studying in silico evolution of complex, oscillatory network dynamics within the framework of a minimal model of protein-protein interactions. We consider N protein species, each with the same total concentration. Each species is either a kinase (activator) or a phosphatase(inhibitor). Each protein can either be phosphorylated(active) or unphospphorylated (inactive). Active proteins bind to
... More

Presented by Mr. MD ZULFIKAR ALI

Type: Contributed talk
Session:
Statistical Mechanics: Jamming, Hard Spheres
Track: Classical statistical mechanics and complex systems

Among the many open questions in nonequilibrium physics, a central issue is whether thermodynamics can be extended to systems far from equilibrium. A specific extension of this nature is steady state thermodynamics (SST), which was proposed some fifteen years ago [1]. Using driven stochastic lattice gases, we ask whether consistent definitions of an effective chemical potential &mu and an effectiv
... More

Presented by Prof. Ronald DICKMAN
on
12 Aug 2014
at
15:00

Computational physics is now widely viewed as an essential ingredient in most undergraduate physics curricula. The challenge, however, is to seamlessly integrate authentic computational activities into the programme. In this talk, I will review the approaches taken at the University of Cape Town, South Africa, where we have developed instructional materials that address the particular needs of our
... More

Presented by Dr. Spencer WHEATON
on
13 Aug 2014
at
15:45

Type: Contributed talk
Session:
Astro Physics 1
Track: Astrophysics, space-plasma physics, gravitation, cosmology

We use an N-body simulation, constructed using GADGET-2, to investigate
an accretion flow onto an astrophysical disk that is in the opposite
sense to the disk's rotation. In order to separate dynamics intrinsic
to the counter-rotating flow from the impact of the flow onto the disk,
we consider an initial condition in which the counter-rotating flow is
in an annular region immediately exte
... More

Presented by Prof. Robert HOHLFELD
on
13 Aug 2014
at
14:45

Type: Poster presentation
Track: Quantum many-body physics

We calculate the spectral function of the one dimensional Hubbard-Holstein model using the time dependent Density Matrix Renormalization Group (tDMRG), focusing on the regime of large local Coulomb repulsion, and away from electronic half-filling. We argue that, from weak to intermediate electron-phonon coupling,
phonons interact only with the electronic charge, and not with the spin degrees of f
... More

Presented by Mr. Mohammad SOLTANIEH-HA

Type: Poster presentation
Track: Classical statistical mechanics and complex systems

We study the convergence of the density of states and thermodynamic properties in three flat-histogram simulation methods, the Wang-Landau (WL) algorithm [1], the 1/t algorithm [2], and tomographic sampling (TS) [3]. In the first case the refinement parameter f is rescaled (f -> f/2) each time the flat-histogram condition is satisfied, in the second f ~ 1/t after a suitable initial phase, while in
... More

Presented by Prof. Ronald DICKMAN

We present a formalism [1-2] for investigating transition pathways and transition probabilities for rare events in biomolecular systems. The formalism is based on combining Transition Path Theory (TPT) with the results of the nonequilibrium work relations, and shows that the equilibrium and nonequilibrium transition rates are in fact related. Aside from its fundamental importance, this allows for
... More

Presented by Prof. Christopher ROLAND
on
11 Aug 2014
at
17:00

Type: Poster presentation
Track: Materials science and nano science

We have systematically investigated the structural, electronic and phase transition properties of the heaviest lanthanide lutetium nitride (LuN) compound using an ab initio calculations based on the density functional theory with Perdrew, Burke and Ernzerhof generalized gradient approximation (PBE-GGA) and Engel-Vosko(EV)-GGA as implemented in WIEN2k code. The basic ground state properties viz., l
... More

Presented by Mr. SANJAY KUMAR SINGH

The Department of Computer Science at Iowa State University has developed a Computational Thinking Competition. It seeks to introduce K-12 students to problem solving with computational thinking in the context of their current coursework in Iowa schools. Student projects are in the form of computational models that help students to understand a problem, understand all of the requirements for a sol
... More

Presented by Prof. Beate SCHMITTMANN
on
12 Aug 2014
at
16:45

Type: Invited talk
Session:
Statistical Mechanics: Networks
Track: Classical statistical mechanics and complex systems

Networks are of broad interest in physics, biology, engineering, and many other areas for the light they shed on the shape and function of complex systems. This talk will focus on the large-scale structure of networked systems -- what do they look like when you stand back and take in the whole network? This is a difficult question to answer because in most cases the networks we study are too lar
... More

Presented by Prof. Mark NEWMAN
on
11 Aug 2014
at
15:45

In the last two decades, the Lattice Boltzmann (LB) method
has attracted major interest as a very versatile
and efficient computational scheme
for the numerical simulation of complex fluid problems across a
broad range of scales, from fluid turbulence, to soft-glasses, all the way down to relativistic quark-gluon plasmas.
In this talk, after introducing the basic ideas behind the
LB me
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Presented by Prof. Sauro SUCCI
on
11 Aug 2014
at
09:15

Type: Invited talk
Session:
Lattice Gauge Theory 1
Track: Lattice field theory in particle and nuclear physics

The strong interaction is a force which binds quarks, antiquarks and gluons together into protons, neutrons and other similar particles. This force is also responsible for binding protons and neutrons into nuclei. The theory which describes the strong interaction is Quantum Chromodynamics (QCD). It is part of the so-called standard model of particle physics, which successfully describes almost all
... More

Presented by Prof. Aida EL-KHADRA
on
12 Aug 2014
at
14:00

Type: Invited talk
Session:
Lattice Gauge Theory 1
Track: Lattice field theory in particle and nuclear physics

To test our current understanding of the fundamental law of particle physics, accurate theoretical calculations and precise experimental results are needed to meaningfully confront each other. The anomalous magnetic moment of muon, (g-2)_mu, provides one of the most stringent tests of this kind. Current and future experimental accuracies, 0.54 ppm and 0.14 ppm, respectively, require theoretical ca
... More

Presented by Dr. Taku IZUBUCHI
on
12 Aug 2014
at
13:30

Type: Contributed talk
Session:
Lattice Gauge Theory 1
Track: Lattice field theory in particle and nuclear physics

We calculate the leptonic decay constants fB and fBs and semileptonic form factors for B->pi l nu and Bs->K l nu in lattice QCD using domain-wall light quarks and nonperturbatively tuned relativistic b-quarks. We present results with a complete systematic error budget based on simulations with two lattice spacings a~0.11 and 0.08 fm and five sea-quark ensembles with pion masses as light as 290 MeV
... More

Presented by Dr. Oliver WITZEL
on
12 Aug 2014
at
14:45

Major challenge impeding cost-effective biofuel production from plant biomass stems from its recalcitrance nature towards degradation into biomass components. Lignin is the main cause of this resistance. In plant cell walls, lignin is derived form radical polymerization of substituted phenyl propylene units: p-coumaryl, coniferyl and sinapyl alcohol. Reducing lignin content or altering monomer com
... More

Presented by Dr. Amandeep SANGHA
on
14 Aug 2014
at
09:15

Type: Poster presentation
Track: Materials science and nano science

We have analyzed the localization of envelop functions in dome-shaped InAs/GaAs quantum dots (QDs) under presence/absence of the wetting layer, size variations, and the Woods-Saxon (WS) potential. The Schrödinger equation was solved numerically using the finite element method for a three-level system. The radius of QDs was varied from 1 to 30 nm, both in the presence and absence of wetting layer
... More

Presented by Mr. Ali KHALEDI NASAB

Blood is a dense suspension of deformable red blood cells (RBCs), which give rise to its complex behaviour in terms of both rheology and cell transport. In the context of thrombus formation in intracranial aneurysms [1], we are interested in the transport of platelets, a process dominated by the motion of RBCs. To inherently capture important phenomena, blood is modelled through its main constitue
... More

Presented by Mr. Lampros MOUNTRAKIS
on
11 Aug 2014
at
15:00

Type: Contributed talk
Session:
Statistical Mechanics: Spin Models 1
Track: Classical statistical mechanics and complex systems

The universal behaviour of two-dimensional loop models can change dramatically when loops are allowed to cross.
We present models with crossings studied by extensive Monte Carlo simulations. Our main focus (the `completely packed loop model with crossings' or CPLC) is a simple generalisation of well-known models which shows an interesting phase diagram with continuous phase transitions of a new
... More

Presented by Mr. Pablo SERNA
on
12 Aug 2014
at
16:15

We will present a unified approach to describe the combined behavior of the atomic and magnetic degrees of freedom in magnetic materials. Using Monte Carlo simulations directly combined with first principles the Curie temperature can be obtained ab initio in good agreement with experimental values.
The large scale constrained first principles calculations have been used to construct effective pot
... More

Presented by Dr. Markus EISENBACH
on
14 Aug 2014
at
08:30

Type: Poster presentation
Track: Quantum many-body physics

Exact diagonalization (ED) has been shown to be a powerful tool to study fractional quantum Hall (FQH) systems. However, its capability is limited by the exponential increase of computational cost with size. In order to overcome this difficulty, Density Matrix Renormalization Group (DMRG) based algorithms were developed to study larger system sizes. Very recently, it was realized that some model F
... More

Presented by Dr. Zhao LIU

Type: Poster presentation
Track: Other areas of computational physics

In computational materials science, Time-Dependent Density Functional Theory (TDDFT) is a powerful tool for calculating the excited states of molecules. In our calculations, the real-time and real-space technique is adopted in solving equations by the finite difference approach [1, 2]. Within the framework of this approach, the wave functions are evolved with the perturbed initial wave function. I
... More

Presented by Mr. Mitsuki TOOGOSHI

A common goal of quantum simulation and quantum computation is the controlled unitary evolution of a quantum state with errors that are known and small. However, it is often the case that control is limited and errors are unknown and possibly large. We consider the case where a large ensemble of identical systems is available and measurements on one subset of systems are used to inform the control
... More

Presented by Dr. Jonathan MOUSSA
on
13 Aug 2014
at
17:15

Real-time evolution of large-scale quantum systems remain a formidable
challenge to address theoretically. Studies with numerical simulations are
hindered by the sign problem. The effect of measurements on the quantum
system will then be considered, and to what extent it helps to simplify
the problem. As a concrete example, we consider a large quantum system
with spins $\frac{1}{2}$ whose dyn
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Presented by Debasish BANERJEE
on
13 Aug 2014
at
17:00

Type: Poster presentation
Track: Quantum many-body physics

By means of path-integral Monte Carlo simulations we compute the ideal shear strength [1] and Peierls Stress in HCP Helium 4, the prototypical bosonic quantum solid. The ideal strength represents a theoretical upper bound of material strength, being defined as the minimum stress required to destabilize a defect-free crystal and produce a plastic deformation. We find that the ideal strength limit i
... More

Presented by Mr. Edgar Josué LANDINEZ BORDA

Active liquid crystals are a new and exciting class of soft matters in which energy is continuously being supplied by internal or external sources. Examples arise in both the physical and biological science realms including bacteria suspensions, active gels and assemblies of motors and filaments. These compound element systems are naturally multiscale as it is activity that yields its peculiar phe
... More

Presented by Prof. Zhenlu CUI
on
14 Aug 2014
at
09:00

Type: Poster presentation
Track: Materials science and nano science

Photocatalysis on semiconductor surfaces is a subject of extensive research in the quest for renewable energy and green materials. Photocatalytic methoxy splitting on rutile TiO<sub>2</sub> (110) surfaces has previously been observed in experiments in vacuum [1]. Here we study the excited-state dynamics of this process using the Ehrenfest approximation within time-dependent density functional theo
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Presented by Grigory KOLESOV

During the last years, we have developed nonadiabatic excited state dynamics methods based on Trajectory Surface Hopping/Linear Response Time-Dependent Density Functional Theory (TSH/LR-TDDFT) [1] and real time propagation TDDFT (PT-TDDFT) based Ehrenfest dynamics [2] and have combined them with mixed quantum mechanical/ molecular mechanical (QM/MM) simulations to study nonadiabatic processes in c
... More

Presented by Prof. Ursula ROTHLISBERGER
on
13 Aug 2014
at
10:30

Type: Poster presentation
Track: Fluid dynamics, magnetohydrodynamic

Jinwang Tan and Emily Ryan
Department of Mechanical Engineering, Boston University, Boston, Massachusetts 02215, USA
Dendrite formation on the anode surface of lithium (Li) air batteries plays a significant role in their performance and safety. We use predictive computational methods to model and investigate the growth and morphology of these dendrites within these complex battery systems.
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Presented by Mr. Jinwang TAN

Direct power extraction via magnetohydrodynamic (MHD) principles offers a potential step improvement in thermal efficiencies over energy systems utilizing traditional turbomachinery. This is principally due to the lack of moving parts in a MHD generator, as the temperature limits of the moving parts tend to limit cycle temperatures in traditional combustion driven systems.
It was established th
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Presented by Mr. Duncan MCGREGOR
on
11 Aug 2014
at
17:15

Type: Invited talk
Session:
Statistical Mechanics: Networks
Track: Classical statistical mechanics and complex systems

A central problem in analyzing networks is partitioning them into modules or communities, clusters with a statistically homogeneous pattern of links to each other or to the rest of the network. A principled approach to address this problem is to fit the network on a stochastic block model, this task is, however, intractable exactly. In this talk we discuss application of belief propagation algorit
... More

Presented by Lenka ZDEBOROVA
on
11 Aug 2014
at
16:15

Type: Poster presentation
Track: Materials science and nano science

Palladium is a precious and rare element that belongs to the Platinum group metals (PGMS) with the lowest density and melting point. Numerous uses of Pd in dentistry, medicine and industrial applications attracted considerable investment. Preparation and characterization of palladium nanoparticles have been conducted by many researchers, but very little effort has taken place on the study of Pd ph
... More

Presented by Dr. Esam ABDUL-HAFIDH

Type: Poster presentation
Track: Soft-matter, polymer, and biological physics

Self-Assembly is the basic mechanism through which structural organizations (both organic and inorganic), are formed from the scale of molecules to the galaxies. Peptide amphiphiles form 1-dimensional nanostructures via the mechanism of Self-Assembly. These nanostructures, in the context of regenerative medicine and tissue engineering, have the potential to be used in the construction of blood v
... More

Presented by Dr. Emine Deniz TEKIN

Advances in simulation methods, continued optimizations of atomistic force fields, and increases in available computational power have coupled together over the past few decades to transform our understanding of biomolecular structure, dynamics, interactions and function. Such methods can aid in the design of new drugs, monitor how RNA and protein molecules fold, and aid in the interpretation of
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Presented by Thomas CHEATHAM
on
11 Aug 2014
at
16:15

Type: Poster presentation
Track: Quantum many-body physics

Recent advances in nanofabrication techniques now allow for the creation of well ordered porous materials based on silicon [1] that provide a route to dimensional confinement of quantum fluids. As the spatial dimension is reduced, we expect enhanced thermal and quantum fluctuations, and such substrates may allow for the experimental study of quasi one dimensional superfluids [2]. It is thus impo
... More

Presented by Mr. Kyle ROBERTSON

Monte Carlo and Molecular Dynamics simulations are powerful tools to study soft matter systems. GPUs are massively parallel compute processors that deliver an order of magnitude faster performance than a multi-core CPU and enable researchers to run larger or longer simulations than previously possible. We present an overview on HOOMD-blue, our open-source GPU accelerated particle simulation toolki
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Presented by Joshua ANDERSON
on
11 Aug 2014
at
16:45

Type: Poster presentation
Track: Soft-matter, polymer, and biological physics

Monte Carlo (MC) methods are useful for simulating systems with many degrees of freedom, such as cellular structures and plant tissues. The recently developed simulation framework VirtualLeaf [1] uses a MC method with Metropolis dynamics for studying plant tissue morphogenesis. In VirtualLeaf the cell and tissue behavior is represented within a generalized energy, i.e. Hamiltonian. It includes the
... More

Presented by Mr. Abdiravuf DZHURAKHALOV

Type: Poster presentation
Track: Quantum many-body physics

In this poster, I will first introduce a quantum Monte Carlo method [1,2]
to characterize spinons (emergent S = 1/2 excitations) by their size and
confinement length. I will then use this method to look for spinon
deconfinement in 2D resonating-valence-bond (RVB) spin liquids and in
a J-Q model hosting a quantum phase transition from an antiferromagnet
to a valence-bond solid (VBS) at zero te
... More

Presented by Dr. Ying TANG

We discuss the instabilities upon the introduction of local Coulomb repulsion and explicit SU(N)-symmetric Heisenberg-like spin exchange to Dirac Fermi-surfaces, quadratic band touching point-like Fermi-surfaces and full Fermi-surfaces. The extension to higher symmetries allows us to study the melting of phases as a function of correlations as well as symmetry. We explore the quantum phases emergi
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Presented by Dr. Thomas C. LANG
on
12 Aug 2014
at
15:00

Type: Contributed talk
Session:
Statistical Mechanics: Spin Models 2
Track: Classical statistical mechanics and complex systems

We perform a competitive analysis to study the relative performance of the two best-known generalized-ensemble algorithms: the multicanonical Monte Carlo and the Wang-Landau method. To keep things as simple and clear as possible, we take the exactly solvable
two-dimensional Ising model as test case and we show also some results for the
three-dimensional Ising model.

Presented by Dr. Elmar BITTNER
on
13 Aug 2014
at
14:30

Type: Poster presentation
Track: Materials science and nano science

We present our experimental studies of two dimensional Tungsten Diselenide (WSe2) atomic films grown on 0001 plane of sapphire substrate with vapor-solid transport method in a 3 feet long three zone horizontal tube furnace. Room temperature Raman scattering and photoluminescence measurements are performed to characterize the sample. We observe well resolved photoluminescence peaks at around 750nm
... More

Presented by Mr. Asanka WEERASINGHE

The challenge of undertaking solving large and complex multiscale and multiphysics calculations on present and future large scale computer architectures is addressed. The computational framework employed is the Utah Uintah software. This software employs a layered approach of an abstract graph-based formulation that generates tasks for a sophisticated runtime system that executes the tasks asynchr
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Presented by Prof. Martin BERZINS
on
12 Aug 2014
at
15:45

Type: Poster presentation
Track: Materials science and nano science

The switching of material atomic structure and electric conductivity are used in novel technologies of making memory on the base of phase change. The possibility of making memory on the base of amorphous carbon is shown in experiment [1]. Present work is directed to simulation of the experimentally observed effects. Ab initio quantum calculations were used for simulation of atomic structure chang
... More

Presented by Dr. Alexander POPOV

We study generalizations of the singlet-sector amplitude-product states in the valence-bond basis of S = 1/2 quantum spin systems. In the standard amplitude-product states, the weight of a tiling of the system into valence bonds (singlets of two spins) is a product of amplitudes depending on the length of the bonds. While the standard amplitude-product states can describe a phase transition betw
... More

Presented by Prof. Yu-Cheng LIN
on
11 Aug 2014
at
15:00

The Framework Programmes were developed as a strategy of the European Commission to enhance research and technology advances in its member countries. In past work, several research groups attempted to assess the FP5 and FP6 effectiveness, using largely statistical methods, and network analysis. Here, we study the data of FP7 following the network approach. The nodes of the network represent the in
... More

Presented by Prof. Panos ARGYRAKIS
on
12 Aug 2014
at
13:30

Type: Poster presentation
Track: Other areas of computational physics

The considerable interest in studying the Hamiltonians associated with the quantum state evolution has been generated while implementing the work of a quantum computer. In this work, we interpret time series data in terms of the objects specific to the quantum computations, namely using unitary transformation matrices and their eigenvalues. We analyze a case of relating two n-qubit long quantum
... More

Presented by Dr. Arman KUSSAINOV

Type: Invited talk
Session:
Statistical Mechanics: Jamming, Hard Spheres
Track: Classical statistical mechanics and complex systems

I describe a new algorithm to generate a diverse class of jammed disordered and ordered sphere packings with very high fidelity across Euclidean space dimensions. The task is posed as an optimization problem that is solved using linear programming techniques [1]. I will discuss how the algorithm leads to efficient generation of the densest sphere packings in high dimensions [2], a problem of impor
... More

Presented by Prof. Salvatore TORQUATO
on
12 Aug 2014
at
14:00

Recent high accuracy non-BO calculations of small diatomic molecules employing explicitly correlated Gaussian basis set have revealed some interesting non-adiabatic effects. The approach can be extended to study more exotic (including muonic) systems which challenge researchers to use more efficient software and hardware paradigms.
Some of the possible approaches are discussed and
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Presented by Nikita KIRNOSOV
on
12 Aug 2014
at
14:30

Type: Contributed talk
Session:
Statistical Mechanics: Spin Models 1
Track: Classical statistical mechanics and complex systems

We note that the standard inverse system volume scaling for finite-size corrections at a first-order phase transition (i.e., 1/L^3 for an L × L × L lattice in 3D) is transmuted to 1/L^2 scaling if there is an exponential low-temperature phase degeneracy. The gonihedric Ising model which has a four-spin interaction, plaquette Hamiltonian provides an exemplar of just such a system. We use multican
... More

Presented by Prof. Wolfhard JANKE
on
12 Aug 2014
at
16:45

Materials are prime enabler of technology. Metamaterial has been a transformative field where by engineering elements in a building block unique phenomena could be achieved. In this presentation we will demonstrate by using only two types of materials, a positive dielectric and a negative plasmonic, how one can achieve a range of desired material parameters from 0 to infinity (positive and negativ
... More

Presented by Prof. Hossein MOSALLAEI
on
11 Aug 2014
at
14:30

We use quantum Monte Carlo simulations of the two-dimensional Bose-Hubbard model to study the quantum glass emerging from the superfluid and Mott-insulator states in the presence of random potentials. Rare large superfluid domains in a Mott background make the glass gapless although it is insulating. Contrary to the commonly accepted paradigm, we show here that the compressibility $\kappa$ of the
... More

Presented by Prof. Wenan GUO
on
12 Aug 2014
at
14:45

Type: Contributed talk
Session:
Statistical Mechanics: Jamming, Hard Spheres
Track: Classical statistical mechanics and complex systems

Nucleation, crystallization and melting phenomena between phases are one of the most attractive topics in the history of computer simulation. Since the microscopic mechanism such as particle collective motion is important to understand the macroscopic phase transition, many numerical simulations have investigated after the solid-fluid phase transition in hard sphere system was discovered by conven
... More

Presented by Dr. Masaharu ISOBE
on
12 Aug 2014
at
14:30

Type: Contributed talk
Session:
Lattice Gauge Theory 2
Track: Lattice field theory in particle and nuclear physics

Lattice QCD has recently achieved the point where realistic calculations of proton and neutron structure are possible. Such calculations are currently underway and their results will shed light on a number of outstanding puzzles about nucleon structure, among which are the origin of the proton spin and the more recent enigmatic discrepancy in the proton radius measurements. In addition, studying s
... More

Presented by Dr. Sergey SYRITSYN
on
12 Aug 2014
at
16:45

All theories concerning the decay of isotropic turbulence agree that the turbulent kinetic energy has a power law dependence on time. However, there is still significant disagreement about what the value of the decay exponent should be. The primary theories, proposed by researchers such as von Karman, Saffman, Kolmogorov, and Batchelor, have the decay exponent at values of 1, 6/5, 10/7, 3/2, and
... More

Presented by Prof. Blair PEROT
on
11 Aug 2014
at
17:00

Type: Invited talk
Session:
Astro Physics 2
Track: Astrophysics, space-plasma physics, gravitation, cosmology

Gravitational waves deliver information in exquisite detail about astrophysical phenomena,
among them the collision of two black holes, a system completely invisible to the eyes of electromagnetic telescopes. Models that predict gravitational wave signals from likely sources are crucial for the success of this endeavor. Modeling sources of gravitational radiation requires solving the Einstein eq
... More

Presented by Prof. Deirdre SHOEMAKER
on
14 Aug 2014
at
09:00

Type: Poster presentation
Track: Fluid dynamics, magnetohydrodynamic

With k-e turbulent model, non-cavitating performance of a pump-jet propeller was obtained by calculating RANS equations. The cavitating hydrodynamic performance of it was calculated and analyzed with mixture homogeneous flow cavitation model based on Rayleigh-Plesset equations and sliding mesh. The effects of different inlet velocity ratio, cavitation number and flow velocity on cavitation charact
... More

Presented by Dr. Yao SHI

Type: Poster presentation
Track: Fluid dynamics, magnetohydrodynamic

The LES with Smagorinsky model and the FW-H equation based on Lighthill acoustic theory were adopted to simulate the sound and flow field with different kinds of structures. Based on the analysis of field, drag and flow noise reduction mechanism of the structures with different shapes and sizes was gotten. The result demonstrate preliminarily that the match between the length and diameter of the c
... More

Presented by Prof. Guang PAN

One of the major ongoing debates on the future of quantum annealers pertains to their robustness against the decohering effects of finite temperature and interactions with the environment. We argue that even in an ideal setting of very low temperatures and in the absence of a decohering environment, quantum annealers may find it challenging to solve optimization problems significantly faster tha
... More

Presented by Prof. A. P. YOUNG
on
13 Aug 2014
at
09:15

Type: Contributed talk
Session:
Astro Physics 1
Track: Astrophysics, space-plasma physics, gravitation, cosmology

The availability of general purpose GPUs has made possible their effective usage for scientific computing. Many codes can now run on GPUs with remarkable performance. In astrophysics, Enzo[1] and Ramses[2] are prime examples of such applications. Both are Adaptive Mesh Refinement (AMR) multi-species codes, designed to describe the evolution of cosmological structures, galaxies, gas clouds etc. The
... More

Presented by Dr. Claudio GHELLER
on
13 Aug 2014
at
14:30

Type: Poster presentation
Track: Classical statistical mechanics and complex systems

Sand dunes are found in many places such as deserts, the sea bottom and the surface of Mars. They are formed through interplay between sand and air flow or water flow. When a strong flow blows, sand grains are dislodged from the sand surface. The entrained sand grains collide with the ground and are sometimes deposited. This process takes place repeatedly, resulting in the formation of a dune. The
... More

Presented by Dr. Atsunari KATSUKI

Type: Poster presentation
Track: Materials science and nano science

A first-order plasma phase transition was predicted by Norman and Starostin [1,2] similar to the Van der Waals equation from the competition of short-range quantum repulsion, long-range effective Coulomb attraction and temperature. The hypothesis initiated theoretical works, see e.g. [3,4]. Experimental evidences are obtained for shock-compressed hydrogen [5-7] and at static pressures [8].
The
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Presented by Prof. Genri NORMAN

Solar-based hydrogen production by photocatalytic water splitting offers a route towards the delivery of clean fuel. Semiconductor metal oxides have been typically employed to mediate the photon-induced catalytic process but a comprehensive description of the elementary reaction pathways and charge-carrier dynamics is largely lacking even for the widely used TiO2. We performed Ehrenfest molecular
... More

Presented by Georgios TRITSARIS
on
13 Aug 2014
at
16:30

Computing, and thus software, is one of the foundations of modern physics research and education. It is used for simulation, data analysis, statistical modeling, symbolic manipulation, experimental control, etc. The software we use for these activities has a profound affect on human behavior, attitudes and thought patterns. In this talk I will describe open source software tools and development pa
... More

Presented by Dr. Brian GRANGER
on
13 Aug 2014
at
11:15

Type: Poster presentation
Track: Materials science and nano science

Waste heat can be considered as a major resource of energy. In this case we are able to design next generation of thermoelectric converters that enable us to recover large amounts of waste heat back into useful electric energy [1].
Thermoelectric efﬁciency is given by a dimensionless ﬁgure of merit ZT defined by S<sup>2</sup>σ/(κ<sub>e</sub>+κ<sub>L</sub>). ZT depends on Seebeck coefficien
... More

Presented by Ms. Seyedeh Nazanin KHATAMI

Previously, the ferromagnetism in GaMnAs has been known to be induced by the p-d exchange interaction of the valence holes and localized d-electrons of Mn atoms [1,2]. Recently, some experiments have reported that the Fermi level locates in the d-band inside the band gap [3], which suggests that the ferromagnetism in GaMnAs would be caused by the ferromagnetic double exchange between d-electrons o
... More

Presented by Dr. Van An DINH
on
14 Aug 2014
at
09:00

Reducing computational time with a PIC (particle-in-cell) algorithm is important because there are many physical situations that need to be modeled at the particle level that require large computational times. The goal of this work is to investigate the effect of using multiple Poisson equation solves within one time step of a PIC simulation. The hope of this investigation was the overall computat
... More

Presented by Dr. Junxue REN
on
11 Aug 2014
at
14:45

Type: Poster presentation
Track: Quantum many-body physics

We determine the ground state phase diagram of a one dimensional Bose-Fermi Hubbard model with spin-full fermions using the Density Matrix Renormalization Group (DMRG) method. We focus on the regime with one fermion per site, and deep into the superfluid bosonicphase. We study the effects of the boson-fermion attraction on the fermionic pairing, as a function of the interaction strength, hopping,
... More

Presented by Dr. Alberto NOCERA

Parallel programing is of great importance for computational practitioners but it is almost never incorporated into introductory computational physics courses. This paper describes the adaption of Alan Kaminsky’s parallel Java code library for use in the Easy Java Simulations (EJS) authoring and modeling tool. Using EJS instructors can easily introduce parallel programming techniques such as sp
... More

Presented by Dr. Wolfgang CHRISTIAN
on
13 Aug 2014
at
16:45

Type: Poster presentation
Track: Soft-matter, polymer, and biological physics

We present a partition function zeros analysis for semi-flexible homopolymers considering chain lengths from 10 to 55 monomers.
The zeros were calculated from the estimate density of states obtained by a two-dimensional variant of Wang-Landau sampling.
We aim to verify weather this method is capable or not of finding the indications of the same transitions as we have already identified using mea
... More

Presented by Ms. Sarra DOUAH

Type: Poster presentation
Track: Classical statistical mechanics and complex systems

We present universal framework for generation, analysis and control of
non-trivial states/patterns in the complex systems like kinetic/BBGKY
hierarchies describing general set-up for non-equilibrium dynamics and
their important reductions [1].
We start from the proper underlying functional spaces and their internal
hidden symmetries which generate all dynamical effects. The key
ingredients
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Presented by Mrs. Antonina FEDOROVA, Dr. Michael ZEITLIN

Type: Poster presentation
Track: Classical statistical mechanics and complex systems

We present a Monte Carlo study of a 2 dimensional o-lattice Susceptible-Infected-Recovered (SIR) Model system with connections ruled by a long-range probability distribution of occurence given by a power law decreasing funtion with a characteristic exponent alpha. We considered several situations by fixing the probability of recovery "Pr" and the populational density "d" of the system, in order
... More

Presented by Dr. Henio REGO

Persistent patterns in periodically driven dynamics have been reported in a wide variety of contexts ranging from table-top and ocean-scale fluid mixing systems. We first illustrate a common framework for the emergence of these patterns by considering a simple measure of structure maintenance provided by the average radius of the scalar distribution in transform space. We then consider the importa
... More

Presented by Christopher AMEY
on
11 Aug 2014
at
16:45

Type: Poster presentation
Track: Soft-matter, polymer, and biological physics

Multiple-component physiologic systems, such as the cardiac and respiratory system, exhibit complex dynamics that are further influenced by intrinsic feedback mechanisms controlling their coupling. The nature of cardio-respiratory coupling, and whether it changes with transitions across different states and conditions is not understood. Since key scale-invariant, fractal, linear and nonlinear prop
... More

Presented by Dr. Ronny BARTSCH

Type: Poster presentation
Track: Classical statistical mechanics and complex systems

We study the phase transitions in the nonlinear XY model with four-fold symmetry-breaking field using Monte Carlo simulation method.We show that, without the symmetry-breaking field, the transition is still KT-like when the nonlinearity is not strong, but turns to first order when the nonlinearity is strong enough. With four-fold symmetry-breaking field present, the transition turns to continuous
... More

Presented by Mr. Zhenjiu WANG

Solar thermal fuels (STFs) are an unconventional paradigm for solar energy conversion and storage which is attracting renewed attention. A material absorbs sunlight and stores the energy chemically via an induced structural change, which can later be reversed to release the energy as heat. Two important factors for STFs are the absorption cross-section and the quantum yield for photoisomerization.
... More

Presented by David A. STRUBBE
on
13 Aug 2014
at
16:45

Type: Poster presentation
Track: Soft-matter, polymer, and biological physics

The human organism is a complex network of interconnected organ systems, where the behavior of one system affects the dynamics of other systems. Due to these interactions, failure of one system can trigger a breakdown of the entire network. With transitions across physiologic states (e.g., sleep-stages), the dynamics of physiologic systems as well as their interaction may change. Identifying and q
... More

Presented by Dr. Kang LIU

Type: Contributed talk
Session:
Lattice Gauge Theory 3
Track: Lattice field theory in particle and nuclear physics

I will discuss recent results on correlations between Polyakov loops in two different directions on a finite torus for two dimensional QCD. Analytical results for SU(2) will be combined with numerical results for SU(N) with N > 2. The behavior at infinite N will also be discussed.

Presented by Prof. Rajamani NARAYANAN
on
14 Aug 2014
at
09:45

Type: Contributed talk
Session:
Statistical Mechanics: Spin Models 2
Track: Classical statistical mechanics and complex systems

Systems with rough free energy landscapes such as spin glasses are difficult to simulate using conventional Monte Carlo methods. Population annealing is a Monte Carlo method for sampling the equilibrium states of systems with rough free energy landscapes. I will introduce the algorithm and then present simulation results for the three-dimensional Edwards-Anderson model. I will discuss the stren
... More

Presented by Mr. Wenlong WANG
on
13 Aug 2014
at
14:00

We describe a quantum algorithm that generalizes the quantum linear system algorithm [Harrow et al., Phys. Rev. Lett. 103, 150502 (2009)] to arbitrary problem specifications. We develop a state preparation routine that can initialize generic states, show how simple ancilla measurements can be used to calculate many quantities of interest, and integrate a quantum-compatible preconditioner that grea
... More

Presented by Dr. David CLADER
on
13 Aug 2014
at
15:45

Traditional high performance computing is capable of focusing tremendous amounts of sustained state-of-the-art computational resources onto physics applications over extended periods of time using batch style operating environments. In addition to this mode of HPC, there is an increasing demand for more complex workflows that involve large fluctuations in the levels of HPC physics computations re
... More

Presented by Patrick DREHER
on
13 Aug 2014
at
17:00

The hydrophobic-polar (HP) model [1] has served as a coarse-grained lattice protein folding model (“an Ising model” for protein folding) attracting scientists from various disciplines because of its simplicity yet challenging computational complexity. Wang-Landau sampling [2,3] combined with pull and bond-rebridging moves has shown to provide a powerful computational means to shed new light on
... More

Presented by Mr. Guangjie SHI
on
12 Aug 2014
at
15:00

Among the new phases of matter sought in the 21st century, two-dimensional quantum spin liquids (QSL) are particularly coveted due to their promise of revolutionizing not only materials science and technology, but also our fundamental understanding of the structure of condensed-matter theory. Despite their importance, concrete knowledge of the microscopic mechanisms that cause magnetic moments
... More

Presented by Prof. Roger MELKO
on
12 Aug 2014
at
14:30

Type: Poster presentation
Track: Quantum many-body physics

We construct some universal picture for re-consideration of base states
and generic phenomena, like entanglement, in Quantum Mechanical set-up.
Our main goal is related to the analytical continuation of the standard
zoo of solutions/base states from trivial ones, like plane waves or gaussians
to novel states, possibly realizable, which permit more realistic
(re)interpretation of the base
fol
... More

Presented by Dr. Michael ZEITLIN, Mrs. Antonina FEDOROVA

Type: Poster presentation
Track: Quantum many-body physics

We use quantum Monte Carlo methods to study the disordered quantum spin systems. Firstly, we use the SSE QMC to study the disordered S=1/2 quantum spins on the square lattice with three different nearest neighbor interactions J1, J2 and J3. Here J1 represents weak bonds, and J2 and J3 correspond to stronger bonds which are randomly distributed on columnar rungs forming coupled 2-leg ladders. By tu
... More

Presented by Prof. Daoxin YAO

We have developed software that makes it very simple for a non-expert to simulate quantum spin systems. It allows one to define a quantum Hamiltonian by drawing dots (for spins) and lines (for bonds), and the values of physical parameters are varied by clicking and dragging sliders. This software was developed by undergraduate physics students using Easy Java Simulations (EJS),[1] and it can be
... More

Presented by Dr. Larry Engelhardt ENGELHARDT
on
12 Aug 2014
at
13:45

Time-dependent density functional theory (TDDFT) is one of the most prominent and widely used methods for calculating excited states of medium-to-large molecules, and it is recognized as a powerful tool for studying electronic transitions of molecules [1]. In our calculations, the real-time and real-space technique is adopted in solving equation by the finite difference approach [2]. In particular
... More

Presented by Prof. Yasunari ZEMPO
on
12 Aug 2014
at
17:15

Tensor networks are a class of variational wave functions enabling an efficient representation of quantum many-body states, where the accuracy can be systematically controlled by the so-called bond dimension. A well known example are matrix product states (MPS), the underlying tensor network of the famous density matrix renormalization group (DMRG) method, which has become the state-of-the-art too
... More

Presented by Dr. Philippe CORBOZ
on
12 Aug 2014
at
14:00

Algorithmic progresses over the last ten years have made it possible to simulate quantum field theories on the lattice taking fully into account the contributions stemming from the fermion determinant. As a consequence lattice gauge theories have become a prime tool to study not only QCD at the physical point, but also strongly-interacting theories beyond QCD. The latter theories could play an imp
... More

Presented by Prof. Luigi DEL DEBBIO
on
14 Aug 2014
at
13:30

Type: Poster presentation
Track: Quantum many-body physics

We investigated a SQUID structure formed by a spin-orbit coupling nanowire Josephson junction which contains Majorana fermions, and a conventional superconductor-insulator-superconductor junction [1], motivated by a recent experimental progress in realizing Majorana fermions in a heterostructure of a spin-orbit coupling nanowire and superconductor [2]. It is shown that the critical current of the
... More

Presented by Prof. Zhi WANG

Rejection-free, Irreversible, and Infinitesimal Monte Carlo Algorithms and Melting in two dimensions

Type: Invited talk
Session:
Statistical Mechanics: Jamming, Hard Spheres
Track: Classical statistical mechanics and complex systems

I show how the lifting principle and a new pairwise decomposition of the Metropolis filter allows one to design a class of powerful rejection-free Markov-chain Monte Carlo algorithms that break detailed balance yet satisfy global balance. These algorithms generalize the recent hard-sphere event-chain Monte Carlo method.
As an application, I present recent progress in our understanding of the pha
... More

Presented by Dr. Werner KRAUTH
on
12 Aug 2014
at
13:30

Type: Contributed talk
Session:
Statistical Mechanics: Networks
Track: Classical statistical mechanics and complex systems

Parallel simulations are widely used nowadays, both in science and industry. It is clear that realistic models of scalable hardware and software should be dynamic, asynchronous, and quite inhomogeneous in time, and should use new methods of synchronization. One of the approaches based on the decomposing of simulation onto logical processes which synchronization can be performed using optimistic or
... More

Presented by Prof. Lev SHCHUR
on
11 Aug 2014
at
17:00

We propose a new class of tensor networkstates, named as projected entangled simplex states (PESS), for studying ground state properties of quantum lattice models. It extends the pair correlation in the projected entangled pair states (PEPS) to a simplex. The PESS is an exact repre-sentation of the so-called simplex solid states and an efficient trial wavefunction that satisfies the area law of en
... More

Presented by Prof. TAo XIANG
on
13 Aug 2014
at
14:00

Type: Poster presentation
Track: Other areas of computational physics

The research activities of the high-performance computational physicists are analyzed by scientometric approaches. This study aims at providing high-performance computational physicists and policy planners with useful scientometric results for an assessment of research activities. In order to achieve this purpose, we carried out a co-authorship network analysis of journal articles to assess the re
... More

Presented by Ms. Sul-Ah AHN

The paper describes the software infrastructure of the ParInt package for multivariate numerical integration, layered over a hybrid parallel environment with distributed memory computations (on MPI), and multi-threaded components running on the nodes and many-core accelerators.
ParInt supports the computation of multivariate integrals over hyper-rectangular and simplex regions. The algorithms
... More

Presented by Prof. Elise DE DONCKER
on
12 Aug 2014
at
17:00

Type: Poster presentation
Track: Classical statistical mechanics and complex systems

We are interested in how cognitive function can emerge from the collective behaviour in biologically inspired networks of neurons. In particular we use the dynamics of stable attractors in the form of subsets of neurons that (transiently) synchronize when a very particular sensory stimulus is presented as a many-body pattern recognition algorithm.
We test these notions in a model of olfaction
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Presented by Mr. Bolun CHEN

Recently it is found that accumulation of a time-evolving wavepacket in chaotic billiards makes scar-like localization [1,2], It emerges along classical unstable periodic orbits, when the wavepackets are launched along the orbits. Sufficiently long time after launching, the wavepacket spread all over the billiards and does not seemingly express any particular texture besides randomly granular pa
... More

Presented by Prof. Mitsuyoshi TOMIYA
on
12 Aug 2014
at
14:45

Type: Contributed talk
Session:
Astro Physics 2
Track: Astrophysics, space-plasma physics, gravitation, cosmology

The self-gravitational instability in interstellar molecular cloud is investigated considering the effect of dust-neutral collisions, magnetic field and polarization force. The modified dynamic of dusty plasma are discussed and gravitational modes are obtained with a linear dispersion relation. The dynamics of self-gravitating charged dust grain and neutral particles are considered and low frequen
... More

Presented by Dr. R K CHHAJLANI
on
14 Aug 2014
at
09:30

Type: Poster presentation
Track: Soft-matter, polymer, and biological physics

We report computational studies of the behavior of semi-flexible polymers in disordered media. An off-lattice chain growth algorithm based on the Monte Carlo method is used to examine configurational properties of the polymers such as the end-to-end distance and tangent-tangent correlation. Particular attention is paid to the effects of the disordered environment on the properties of the polymers.
... More

Presented by Mr. Johannes BOCK

Type: Contributed talk
Session:
Lattice Gauge Theory 2
Track: Lattice field theory in particle and nuclear physics

Semimetal-Insulator transition arises when massless Dirac fermions become massive due to inter-
actions through the mechanism of spontaneous symmetry breaking. In most cases this occurs when
some fermion bilinear order parameter becomes non-zero in the insulator phase. Here, we explore the
possibility of Dirac fermions acquiring a mass through interactions, but without such an order parameter.
... More

Presented by Mr. Venkitesh AYYAR
on
12 Aug 2014
at
17:00

Type: Poster presentation
Track: Materials science and nano science

We have carried out a numerical simulation to investigate the optical and electronic properties of InAs/GaAs Quantum dots (QDs). The main contribution of this paper is investigating linear and nonlinear optical properties as well as distribution of envelope functions on different shape of QDs in presence and absence of wetting layer. In absence of wetting layer the dome, conical, cylindrical, elli
... More

Presented by Mr. Ali KHALEDI NASAB

Type: Poster presentation
Track: Soft-matter, polymer, and biological physics

Shear plays a dominant role in shaping the collective behavior of systems where thermal fluctuations are irrelevant. Recent studies of athermal systems such as dry grains and dense, non-Brownian suspensions have shown that shear can lead to solidification through the process of shear jamming in grains and discontinuous shear thickening in suspensions. The similarities observed between these two d
... More

Presented by Mr. Sumantra SARKAR

Type: Contributed talk
Session:
Statistical Mechanics: Jamming, Hard Spheres
Track: Classical statistical mechanics and complex systems

The relation between the dynamics of glass-forming liquids [1] and properties of the potential energy landscape visited by the system during its time-evolution has been a subject of extensive investigations [2]. However, a clear interpretation of the short-time β relaxation of glass-forming liquids in terms of dynamics in the potential energy landscape is not yet available. We have studied the re
... More

Presented by Prof. Chandan DASGUPTA
on
12 Aug 2014
at
14:45

Type: Poster presentation
Track: Classical statistical mechanics and complex systems

We study a lattice model for vector-mediated transmission of a disease in a population consisting of two species, A and B, which contract the disease from one another. Individuals of species A are sedentary, while those of species B (the vector) diffuse in space. Examples of such diseases are malaria, dengue fever, and Pierce's disease in vineyards. The model exhibits a phase transition between an
... More

Presented by Dr. Adriana GOMES DICKMAN

Type: Poster presentation
Track: Soft-matter, polymer, and biological physics

Bio-sensors based on the detection of FRET (Foster Resonance Energy Transfer) luminescence are extensively used in molecular biology to identify spatio-temporal protein interactions invitro towards understanding biochemical pathways.[1] FRET bio-sensing systems generally consist of two interacting proteins in solution that carry different FRET donor and acceptor chromophores which can exchange exc
... More

Presented by Mr. Shourjya SANYAL

Galaxies are the way by which we mark out the evolution of our Universe. Whether we use them to measure dark energy, study how stars form, explore the final frontier of reionization, or study them for their own sake, the problem of galaxy formation is a rich and long-standing area of astrophysics that remains remarkably poorly understood. This talk will give a brief introduction to the study of
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Presented by Prof. Romeel DAVé
on
14 Aug 2014
at
14:15

The density matrix renormalization group (DMRG) has become the standard approach
for simulating strongly correlated electron systems in one dimension. Recent
progress has allowed DMRG to be used for two dimensional systems, most notably
in finding that the kagome lattice Heisenberg model has a spin liquid ground state.
Recently, the matrix product wavefunctions produced by DMRG have been shown
... More

Presented by Prof. Steven WHITE
on
14 Aug 2014
at
11:15

Monte Carlo simulations of Ising models generate spin configurations with Boltzmann probabilities. An inverse problem starts with spin configurations and has the goal of finding the interaction parameters. The problem first arose in the determination of renormalized coupling constants from Monte Carlo renormalization group simulations, and a general solution was found using correlation function
... More

Presented by Prof. Robert SWENDSEN
on
12 Aug 2014
at
16:30

The study of spin glasses (SG's) has been an active research field
for the last three decades. The importance of the systems lies in the fact that they have some significance not only for other parts of physics, but also for such fields as computer science, mathematics and biology, including many technological applications. They are a class of random magnets with rich physical properties, such
... More

Presented by Dr. Tasrief SURUNGAN
on
13 Aug 2014
at
14:15

Atomic gases cooled to Nanokelvin temperatures are a new exciting tool to study a broad range of quantum phenomena. In particular, an outstanding and rapid control over the fundamental parameters, such as interaction strength, spin composition, and dimensionality allows to realize and observe many different situations far from equilibrium. One of the fundamental questions is the spreading of corre
... More

Presented by Prof. Corinna KOLLATH
on
13 Aug 2014
at
13:30

Type: Poster presentation
Track: Soft-matter, polymer, and biological physics

The stabilization of secondary structure is believed to play an important role in the peptide-protein binding interaction. In this study, the α-helical conformation and structural stability of single and double stapled all-hydrocarbon cross-linked p53 peptides when bound and unbound to MDM2 are investigated. We determined the effects of the peptide sequence, the stereochemistry of the cross-linke
... More

Presented by Ms. Kristina STREU

My ten-week MOOC on the Coursera platform, that ran in early 2014, focused on subjects such as Monte Carlo sampling, molecular dynamics, phase transitions in hard-sphere liquids, simulated annealing, classical spin models, quantum Monte Carlo algorithms, and Bose-Einstein condensation, etc. It familiarized a huge international crowd of students with cutting-edge subjects in computational physics
... More

Presented by Dr. Werner KRAUTH
on
13 Aug 2014
at
17:15

Type: Poster presentation
Track: Quantum many-body physics

We apply a series of projection techniques on top of tensor networks to compute energies of ground state wave functions with higher accuracy than tensor networks alone with minimal additional cost. We consider both matrix product states as well as tree tensor networks in this work. Building on top of these approaches, we apply fixed-node quantum Monte Carlo, Lanczos steps, and exact projection. We
... More

Presented by Dr. Hitesh CHANGLANI

We studied mechanical and electronic properties of graphene by strain engineering nano-structures in two-dimensional and three-dimensional deformations. By using a combined atomistic simulation approach with molecular mechanics, molecular dynamics, tight binding and Landauer-Buttiker formalism, we explored possible deformation patterns to induce tunable pseudomagnetic field (PMF) distributions and
... More

Presented by Mr. Zenan QI
on
12 Aug 2014
at
16:15

We discuss the challenge and bottlenecks in scaling a GPU molecular dynamics code, HOOMD-blue 1.0, up to 1000’s of GPUs. We show performance data on the Titan supercomputer, and compare to the LAMMPS molecular dynamics software. HOOMD-blue’s scaling capabilities are particularly well suited for large-scale simulation of polymer systems or particle fluids. We demonstrate how the recently develo
... More

Presented by Dr. Jens GLASER
on
11 Aug 2014
at
17:00

A physical model consists of conservation laws, equilibrium conditions, definitions and constitutive relations, [1]. The conservation laws, equilibrium conditions and definitions are so-called <em>topological relations</em>. More specifically, these topological relations are <em>independent</em> of metric. The topological relations are divided into two disjoint classes which we refer to as <em>out
... More

Presented by Dr. Marc GERRITSMA
on
11 Aug 2014
at
15:45

Comparison of computational and experimental data in recent years highlights
the significance of the intrinsic dynamics of proteins in facilitating, or
enabling, biological functions. Intrinsic dynamics refer to the collective
motions encoded in the native structure, predominantly defined by the
network of inter-residue interactions. Elastic network models (ENMs) coupled
with normal mode anal
... More

Presented by Prof. Ivet BAHAR
on
11 Aug 2014
at
15:45

Ceramide bilayers constitute the lipid domain of stratum corneum, the outermost layer of the skin. Ceramides are a special class of lipids that consist of a polar head and two alkyl tails, one of which is sphingosine and the other is a fatty acid. The biological importance of the specific system arises from the fact that it has major contribution to the barrier function of the skin.
In this work,
... More

Presented by Dr. Nikolaos PAPADIMITRIOU
on
14 Aug 2014
at
09:30

Type: Poster presentation
Track: Materials science and nano science

In this study, the electronic and magnetic properties of (Fe2O3)n (n = 2-5) clusters were studied using Density Functional Theory. It came out that the most stable structures for n = 2, 3 and n = 4, 5 were ferrimagnetic and antiferromagnetic, respectively. The states with completely geometrical symmetry were spin-symmetric also, i.e. had equal atomic magnetic moments. It was found that by increasi
... More

Presented by Ms. SHOLEH ALAEI

Type: Poster presentation
Track: Soft-matter, polymer, and biological physics

The big class of solvents with are considered promising to replace organic solvents in industrial processes, are ionic liquids and the use them as solvents for different processes on industrial and pilot plant scale gains more and more interest. The study showed that an ionic liquid based process can be economical more beneficial than conventional processes.
In the present study includes we repo
... More

Presented by Dr. N. ATAMAS

Type: Poster presentation
Track: Materials science and nano science

Carbon material is employed for the plasma facing material in plasma experimental device. For example, isotropic graphite materials are used for the divertor plates of Large Helical Device (LHD) in National Institute for Fusion Science, Japan. Development of the control technique of the surface erosion and hydrogen retention processes are the key issue for the achievement of steady state operation
... More

Presented by Dr. Seiki SAITO

Copolymers are flexible macromolecules that are comprised of two (or more) blocks. The incompatibility between the constituents of different blocks gives rise to microphase separation on the length scale of 5 -70 nm. Much effort has been devoted to utilizing these soft materials as templates for nanostructures, e.g., for integrated circuits and memory devices, and fabricating defect-free structure
... More

Presented by Prof. Marcus MUELLER
on
11 Aug 2014
at
13:30

Type: Poster presentation
Track: Astrophysics, space-plasma physics, gravitation, cosmology

One of the frontiers in modern cosmology is understanding the end of cosmic dark ages, when the first luminous transformed the simple early Universe into a state of ever-increasing complexity. We present multidimensional simulations of the thermonuclear supernovae from the first stars. Numerical and theoretical study of the primordial star formation in the early Universe suggest that these star
... More

Presented by Dr. Ke-Jung CHEN

Type: Invited talk
Session:
Lattice Gauge Theory 3
Track: Lattice field theory in particle and nuclear physics

Attempts to formulate supersymmetric field theories on discrete
spacetime lattices have a long history. However, until recently most
of these efforts have failed. In this talk I will review some of
the new ideas that have finally allowed a solution to this problem for
certain supersymmetric theories. I will focus my attention, in particular, on N=4 super Yang-Mills which forms one of the pilla
... More

Presented by Prof. Simon CATTERALL
on
14 Aug 2014
at
08:30

Type: Contributed talk
Session:
Lattice Gauge Theory 3
Track: Lattice field theory in particle and nuclear physics

The light Higgs boson of the Standard Model could arise as the consequence of the weakly broken conformal symmetry in a strongly interacting gauge theory just below the conformal window. Here we present a novel idea to study the transition from conformal to confining behavior using an SU(3) gauge theory with four light and eight heavy flavors. This system interpolates between the 12 flavor conform
... More

Presented by Mr. Evan WEINBERG
on
14 Aug 2014
at
09:30

Teaching Density Functional Theory through Experiential Learning: Examples from the Developing World

Today, quantum mechanical density functional theory is often the method of choice for performing accurate calculations on atomic, molecular and condensed matter systems. Such calculations provide data that can be used to interpret experiments, gain insight into structure-property relationships, and design novel materials. With recent rapid advances in computational power, it is now possible to per
... More

Presented by Prof. Shobhana NARASIMHAN
on
13 Aug 2014
at
16:15

Though nano-Cu films used extensively in Microelectro Mechanical Systems (MEMS) have been the subject of widespread experimental [1-4] and theoretical [5-7] research, the mechanisms of plastic deformation of them have not fully understood up to the present. Moreover, only a limited portion [2,3] of studies published has been concerned with the aspect of various temperatures. Thus, in the isobaric-
... More

Presented by Prof. Qiao-Neng GUO
on
14 Aug 2014
at
09:30

One of the most challenging aspects of the undergraduate physics curriculum is providing interesting projects that give students meaningful research experience. Computationally-related projects provide a low cost entry into contemporary research, and many problems can be made accessible to undergraduates. Because of the paucity of accessible papers in the research literature, we have started the C
... More

Presented by Prof. Jan TOBOCHNIK, Dr. Harvey GOULD
on
12 Aug 2014
at
17:15

Type: Invited talk
Session:
Astro Physics 1
Track: Astrophysics, space-plasma physics, gravitation, cosmology

The standard cosmological model, which posits that the energy content of the Universe is dominated by two mysterious components (dark matter and dark energy), has been very successful on large cosmological scales. On galactic and sub-galactic scales, however, a number of potential issues have arisen; these issues may point to new fundamental physics or to previously unappreciated processes in gala
... More

Presented by Mike BOYLAN-KOLCHIN
on
13 Aug 2014
at
13:30

Recent developments in supercomputing are reviewed covering both the latest hardware trends and the increasing difficulties faced by scientists in utilising these machines to perform large-scale numerical simulations. The role of one of the major European players in supercomputing, the Julich Supercomputing Centre (JSC) in Germany is described in this context. Since 1986 the primary mission of JSC
... More

Presented by Dr. Norbert ATTIG
on
13 Aug 2014
at
15:45

In 1974, Dennard et al argued that power dissipation of integrated circuits would be independent of circuit density, and that furthermore, same-circuit gate delays would scale with transistor feature size. Moore’s law implied that circuit density would double every two years. Together, these implied that computational power per square inch and computational power per watt should double every 18
... More

Presented by Dr. John DANSKIN
on
12 Aug 2014
at
08:30

Type: Poster presentation
Track: Astrophysics, space-plasma physics, gravitation, cosmology

Thermal mantle plumes in the Earth and other terrestrial planets are responsible for hot spots on the surface. Thermal plumes in the mantles of the terrestrial planets provide an important mechanism for the transfer of heat from the planet’s interior. Theory and experiment both determine the structure of thermal plumes as having a large plume head and a long and narrow plume tail. The gravita
... More

Presented by Dr. Juan H. HINOJOSA

A key research area in the Keyes Lab is focused on studying protein folding and energy landscapes using statistical biophysics techniques. Kim, Straub, and Keyes introduced the Statistical Temperature Molecular Dynamics (STMD) algorithm which has been implemented into the biosimulation package CHARMM. Atomistic simulations using this enhanced sampling algorithm have been performed on the Methionin
... More

Presented by Ms. Shanadeen BEGAY
on
14 Aug 2014
at
08:30

Type: Invited talk
Session:
Astro Physics 1
Track: Astrophysics, space-plasma physics, gravitation, cosmology

Cosmological simulations start from Big Bang initial conditions and simulate a representative volume of the Universe to the present time. They follow the dynamics of dark matter, stars, and gas and have been very successful at explaining the large-scale structure that we measure in the distributions of galaxies and intergalactic gas across cosmic time. Due to finite resolution and an incomplete se
... More

Presented by Dr. Claude-Andre FAUCHER-GIGUERE
on
13 Aug 2014
at
14:00

Type: Poster presentation
Track: Other areas of computational physics

The modeling of positron transport is important in a variety of areas ranging from astrophysics to medical imaging [1]. Positron-specific process such as annihilation significantly modify transport behaviour [2]. In this work we model positron transport using kinetic theory via the Boltzmann equation. The standard approach is to represent the velocity-space by a series of Spherical Harmonics or L
... More

Presented by Dr. Ron WHITE

Type: Poster presentation
Track: Materials science and nano science

As most properties depend on the fine details of local atomic structure, the diagnostic methods to control structural parameters, such as the distances between the atoms, with very high precision are required. In this research X-ray absorption spectroscopy is used to study the geometry of several types of nanomaterials. In addition, a detailed interpretation of the experimental XAS (X-ray Absorpti
... More

Presented by Dr. Victoria MAZALOVA

One of the most commonly suggested applications for a quantum computer is simulating quantum systems. Although clearly promising in the limit of large quantum computers, we explore whether quantum simulations are a practical application area for small quantum computers. We show that, at least for the application of quantum chemistry, the standard algorithms in the worst case require significantl
... More

Presented by Prof. Bryan CLARK
on
13 Aug 2014
at
16:15

Type: Poster presentation
Track: Quantum many-body physics

We use the ground-state projector quantum Monte Carlo and the stochastic series expansion quantum Monte Carlo methods to study the bond-disordered JQ_3 model on the square lattice.
The effects of disorder are investigated by measuring the dimer order parameter, the square of the staggered magnetization, dimer-dimer correlation and spin-spin correlation.

Presented by Mr. Lu LIU

The Onsager-Machlup (OM) functional has been used to define an effective "thermodynamic action" that describes the distribution of pathways as a molecule changes conformations. We use this action to explore rare events: molecular transitions substantially impeded by one or more energy barriers. Using an efficient technique, we sample the OM action and generate transition paths that are constrain
... More

Presented by Patrick MALSOM
on
12 Aug 2014
at
17:15

In the simulation and calculation of the energy A3B5 compounds vary from the amount and spatial orientation. Depending on the number of cores in the cluster and their spatial arrangement of the energy changes periodically with different amplitudes. The arrangement of groups of atomic cores in different directions of space subjects to certain laws of a series. In various directions of the arrangeme
... More

Presented by Aisara AMANOVA, Prof. Kulpash ISKAKOVA
on
13 Aug 2014
at
17:00

I will discuss a new computational physics course at Randolph-Macon College and my attempt to identify where it fits into the larger liberal arts curriculum and why. In doing so, I will describe the goals of the course, the challenges I faced in teaching it, and some lessons learned.

Presented by Dr. Rachele DOMINGUEZ
on
13 Aug 2014
at
17:00

Type: Poster presentation
Track: Astrophysics, space-plasma physics, gravitation, cosmology

We have investigate the occurrence characteristics of ionospheric scintillations, using dual frequency GPS, installed and operated at Indian scientific base station Maitri (71.45S and 11.45E) Antarctica, during December 2009 to December 2010. The scintillation morphology is described in terms of S4 Index. The scintillations are classified into four main categories as Weak (0.2<S4<0.4), Moderate (0
... More

Presented by Prof. P.K Purohit PUROHIT

Type: Poster presentation
Track: Classical statistical mechanics and complex systems

The fourth-order cumulant of the magnetization,the Binder cumulant is determined at the different temperature phases of Ising models on two-dimensional anisotropic lattices with various ferromagnetic foreign-neighbor couplings by the Screw-Antisymmetric Periodic Boundary condition (SAPBC Method) of Monte Carlo techniques. The SAPBC Method, actually, is an extended mixed method of Screw (helica
... More

Presented by Mr. amin NAJAFI

Type: Poster presentation
Track: Classical statistical mechanics and complex systems

Many real networks exhibit a layered structure in which links in each layer reflect the function of nodes on different environments. These multiple types of links are usually represented by a multiplex network in which each layer has a different topology. In real-world networks, however, not all nodes are present on every layer. To generate a more realistic scenario, we use a generalized multiplex
... More

Presented by Ms. Lucila G. ALVAREZ ZUZEK

The recently discovered topological crystalline insulators harbor multiple Dirac surface states protected by a discrete set of crystalline space group symmetries and show immense promise for novel quantum applications. In this talk, I will present a first principles investigation as well as a model Hamiltonian of the nontrivial surface states and their spin and orbital texture in the topological c
... More

Presented by Dr. Hsin LIN
on
12 Aug 2014
at
15:45

Type: Poster presentation
Track: Quantum many-body physics

By using the ground-state projector quantum Monte Carlo simulations[1-2], we study the topological properties of the valence-bond-solid states of the <em>JQ<sub>3</sub></em> model on the square lattice[3-4]. The topological winding number is shown to be an emergent quantum number in the thermodynamic limit for the <em>JQ<sub>3</sub></em> model in the VBS state.

Presented by Ms. Hui SHAO

Quantum materials today can be classified as a function of the strength of Coulomb interactions U and spin orbit coupling $\lambda$, in units of the bandwidth W. At large U lie the 3d transition metal oxides that show phenomena such as colossal magneto- resistance and high Tc superconductivity. In the opposite quadrant we encounter topological band insulators with large $\lambda$ but in weakly cor
... More

Presented by Prof. Nandini TRIVEDI
on
11 Aug 2014
at
11:15

We present lattice Boltzmann models at different scales for the simulation of colloidal drying in the presence of polymers and structure formation in resulting phase-separation fronts. When a drop of colloid polymer mixture is exposed to an environment in which the solvent in which these particles are suspended evaporates an accumulation of non-volotile material at the rim of the drop is observed
... More

Presented by Prof. Alexander WAGNER
on
11 Aug 2014
at
14:30

Type: Poster presentation
Track: Classical statistical mechanics and complex systems

We studied the transport process of overdamped Brownian particles, in a chain of asymmetric cavities, interacting through a hard-core potential. When a force is applied in opposite directions a difference in the drift velocity of the particles inside the cavity can be observed. Previous works on similar systems deal with the low-concentration regime, in which the interaction is irrelevant. In this
... More

Presented by Gonzalo P. SUáREZ

In low-dimensional semiconducting systems, the exciton binding energies are significantly enhanced by the confining effect. Typical examples are found in ideal one-dimensional semiconductors, the single-wall carbon nanotubes (SSWCNs). In these systems, also trions and biexcitons are expected to have large binding energies. Although the enhanced stability of trions and biexcitons had been observed
... More

Presented by Prof. Kenichi ASANO
on
13 Aug 2014
at
16:15

Type: Poster presentation
Track: Quantum many-body physics

Localized defects, unavoidable in real solids, may be simulated in (generically defect-free) cold-atom systems, e.g., via modifications of the optical lattice. We study the Hubbard model on a square lattice with single impurities, pairs of nearby impurities, or lines of impurities using numerically exact determinantal quantum Monte Carlo simulations. In all cases, correlations on the "impurity" si
... More

Presented by Prof. Nils BLUEMER

Organic semiconductors are a highly tunable class of optically active materials that are promising as next-generation photovoltaics. Utilizing these materials for efficient solar energy conversion relies on an understanding their excited-state electronic structure, i.e. how light absorption, charge transfer, and charge transport relate to the properties of their molecular components and are influe
... More

Presented by Sahar SHARIFZADEH
on
13 Aug 2014
at
14:45

Type: Invited talk
Session:
Lattice Gauge Theory 2
Track: Lattice field theory in particle and nuclear physics

I will describe for non-specialists the use of lattice QCD, numerical solution of QCD on a discrete space-time lattice, to calculate the the properties of protons and neutrons, the basic building blocks of nearly all the matter in the observed universe, from first principles. I will then describe recent success[1], after decades of effort, in obtaining agreement with experiment for the charge radi
... More

Presented by Prof. John NEGELE
on
12 Aug 2014
at
15:45

Tensors provide a natural and compact representation for
multidimensional data, and algorithms based on tensor networks have recently found their applications in quantum
physics, quantum information science, quantum chemistry, image/pattern
recognition and data science.
However, programming tensor network algorithms is tedious and error
prone due to the complexity in keeping track of multiple
... More

Presented by Prof. Ying-Jer KAO
on
11 Aug 2014
at
15:45

Type: Invited talk
Session:
Statistical Mechanics: Spin Models 1
Track: Classical statistical mechanics and complex systems

Universal amplitudes play an important role in the numerical study of critical phenomena. We study the finite-size scaling of universal amplitudes in the q-state random-cluster model under the constraint that the total number of occupied bonds is fixed, so that the canonical ensemble applies. We observe that at criticality, new finite-size corrections with exponent y<sub>can</sub>=-|2y<sub>t</sub>
... More

Presented by Prof. Youjin DENG
on
12 Aug 2014
at
15:45

Type: Poster presentation
Track: Quantum many-body physics

For local lattice Hamiltonians, the total number of nonzero matrix elements between manybody states in the worst case scenario scales as the number of sites in the lattice. Therefore the number of operations it takes to apply H to a state should scale as L^d*N. by Acting with H "on the fly" one can produce the sequence of states H^n|psi_0> which can be used to produce the evolved state any time la
... More

Presented by Mr. Phillip WEINBERG

Type: Poster presentation
Track: Soft-matter, polymer, and biological physics

The use of extensive Monte Carlo simulations of coarse- grained protein models allows an accurate study of both equilibrium thermodynamics and folding kinetics. The ability to efficiently and rapidly simulate complete folding trajectories, and to observe thousands of folding-unfolding events, unravels the role played by certain protein properties in the folding process. Here we employ replica-exch
... More

Presented by Dr. Rui TRAVASSO

Type: Poster presentation
Track: Quantum many-body physics

The diagonal element of the 2nd-order reduced density matrix, which is referred to as the pair-density (PD), essentially contains more information on the electron correlation than the electron density. Therefore, the PD functional theory[1-6] that can in principle reproduce the ground-state PD is considered as one of the promising theories to go beyond the conventional density functional theory.
... More

Presented by Prof. Masahiko HIGUCHI

Type: Poster presentation
Track: Materials science and nano science

We have systematically investigated the effects of lithium (Li) on AA and AB stacking sequences of bilayer graphene using density functional theory (DFT). To accurately describe the bonding that occurs in bilayer graphene, the following van der Waals corrected exchange correlation functionals were used, namely, vdW-DF revPBE, vdW-DF C09x and vdW-DF2 C09x. Several configurations that contain two Li
... More

Presented by Dr. Edwin MAPASHA

Variational wave functions represent a very powerful tool to study many-body systems, the Bardeen-Cooper-Schrieffer and Laughlin states being two important examples. In this talk, I will show that extremely accurate wave functions can be constructed to describe the low-energy physics of magnetic systems in presence of frustrating interactions. This is a particularly interesting situation, since ne
... More

Presented by Dr. Federico BECCA
on
12 Aug 2014
at
13:30

Vortex shedding is of fundamental interest in fluid
dynamics, with many applications in physics, engineering, and biology,
with relevance for example in biolocomotion.
Numerical studies of separated flows
using the full governing equations are
numerically expensive, and in practice, low order approximations such as
point vortex or vortex sheet models are often used instead.
These models are
... More

Presented by Monika NITSCHE
on
11 Aug 2014
at
13:30

Rare events are ubiquitous in many biological, chemical and physical processes. Whereas the density of states is known in systems at thermal equilibrium, interesting phenomena often occur in non-equilibrium systems. Computer simulations are widely used to estimate the density of states or transition rates between them. As Brownian dynamic simulation provides computational costs that are inversely
... More

Presented by Prof. Raul TORAL
on
13 Aug 2014
at
15:00

Applying heat to polymer interfaces is a common means of welding polymer components or healing cracks in polymers. Once chains have diffused by their radius of gyration, the properties of the interface should be indistinguishable from those of the bulk. In practice, welds can achieve bulk strength at much shorter times. The mechanism of strength growth is difficult to determine with experiments, b
... More

Presented by Prof. Mark ROBBINS
on
11 Aug 2014
at
14:00

Type: Poster presentation
Track: Other areas of computational physics

In linguistic studies, the academic level of the vocabulary in a text can be described in terms of statistical
physics, by using a "temperature" concept related to the text's word-frequency distribution. Here, we
propose a "comparative thermo-linguistic" technique to analyse a text and to determine what academic
level and thus what target readership its vocabulary is focused toward in any given
... More

Presented by Dr. Henio REGO

Type: Poster presentation
Track: Materials science and nano science

One of the primary aims of theoretical materials science is the accurate determination of the phase diagram of a given substance. Put another way: for a given substance, where in phase space do the phase transitions occur? This question is difficult to answer for solid-solid transitions. Surprisingly, the difficulty is by no means limited to 'realistic' models of solids: the location of the hcp-f
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Presented by Dr. Tom UNDERWOOD