Conference

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Modelling Materials Microstructure Across Scales using Phase Field Methods

Nikolas Provatas McGill University

December 05, 2013

PIRSA:13120012
Building Colloidal Crystals in Anisotropic Media

Colin Denniston Western University

December 05, 2013

PIRSA:13120011
Transition Pathways Connecting Stable and Metastable Phases

An-Chang Shi McMaster University

December 05, 2013

PIRSA:13120010
Monte Carlo Field-Theoretic Simulations Applied to Block Copolymer Melts

Mark Matsen University of Waterloo

December 05, 2013

PIRSA:13120009
O Topology

Randall Kamien University of Pennsylvania

December 05, 2013

PIRSA:13120008
Discussion

Xiao-Gang Wen Massachusetts Institute of Technology (MIT) - Department of Physics

November 08, 2013

PIRSA:13110079
Twist Defects in Topological Systems with Anyonic Symmetries

Jeffrey Teo University of Illinois Urbana-Champaign

November 08, 2013

PIRSA:13110078
Quantum and Classical Anomalies

Michael Stone University of Illinois Urbana-Champaign

November 08, 2013

PIRSA:13110077
Majorana State Properties in Semiconductor and Oxide Superconducting Quantum Wires

Allan MacDonald The University of Texas at Austin

November 08, 2013

PIRSA:13110076
Discussion

Eduardo Fradkin University of Illinois Urbana-Champaign

November 07, 2013

PIRSA:13110075
Quantum quenches & holography

Robert Myers Perimeter Institute for Theoretical Physics

November 07, 2013

PIRSA:13110074
Many-body localization: entanglement, emergent conservation laws, and the structure of eigenstates

Dmitry Abanin

November 07, 2013

PIRSA:13110073

Modelling Materials Microstructure Across Scales using Phase Field Methods

Nikolas Provatas McGill University

December 05, 2013

PIRSA:13120012

Phase field crystal models and their recent extension will be summarized. Their application to non-equilibrium kinetics and phase transformations in materials will be reviewed. In particular, we review new results from applications of this modeling paradigm to solute trapping during rapid solidification of alloys, defect-mediated solid-state precipitation, and magneto-crystalline interactions. We close with a discussion of new complex amplitude representations of PFC models and how these can be used for multi-scale simulations using adaptive mesh refinement methods.
Building Colloidal Crystals in Anisotropic Media

Colin Denniston Western University

December 05, 2013

PIRSA:13120011

Colloids in a liquid crystal matrix exhibit very anisotropic interactions. Further, these interactions can be altered by both properties of the colloid and of the liquid crystal. This gives a potential for creating specific colloidal aggregates and crystals by manipulating the interactions between colloids. However, modelling these interacting colloids in a liquid crystal is very challenging. We use a hybrid particle-lattice Boltzmann scheme that incorporates hydrodynamic forces and forces from the liquid crystal field. I will discuss configurations that we have studied, including chains and a potentially stable colloidal crystal with a diamond lattice structure.
Transition Pathways Connecting Stable and Metastable Phases

An-Chang Shi McMaster University

December 05, 2013

PIRSA:13120010

Phase transitions are ubiquitous in nature. Understanding the kinetic pathways of phase transitions has been a challenging problem in physics and physical chemistry. From a thermodynamics point of view, the kinetics of phase transitions is dictated by the characteristics of the free energy landscape. In particular, the emergence of a stable phase from a metastable phase follows specific paths, the minimum energy paths, on the free energy landscape. I will describe the characteristics of the minimum energy paths and introduce an efficient method, the string method, to construct them. I will use self-assembled phases of block copolymers as examples to demonstrate the power of the method. In particular, I will show how precisely determined transition pathways provide understanding and surprises when we try to connect the different ordered phases of block copolymers.
Monte Carlo Field-Theoretic Simulations Applied to Block Copolymer Melts

Mark Matsen University of Waterloo

December 05, 2013

PIRSA:13120009

Monte Carlo field-theoretic simulations (MC-FTS) are performed on melts of symmetric diblock copolymer for invariant polymerization indexes extending down to experimentally relevant values of N=104. The simulations are performed with a fluctuating composition field, W-(r), and a pressure field, W+(r), that follows the saddle-point approximation. Our study focuses on the disordered-state structure function, S(k), and the order-disorder transition (ODT). Although short-wavelength fluctuations cause an ultraviolet (UV) divergence in three dimensions, this is readily compensated for with the use of an effective Flory-Huggins interaction parameter, ce. The resulting S(k) matches the predictions of renormalized one-loop (ROL) calculations over the full range of ceN and N examined in our study, and agrees well with Fredrickson-Helfand (F-H) theory near the ODT. Consistent with the F-H theory, the ODT is discontinuous for finite N and the shift in (ceN)ODT follows the predicted N-1/3 scaling over our range of N.
O Topology

Randall Kamien University of Pennsylvania

December 05, 2013

PIRSA:13120008

Yes, quite. But also with some applications.
Discussion

Xiao-Gang Wen Massachusetts Institute of Technology (MIT) - Department of Physics

November 08, 2013

PIRSA:13110079
Twist Defects in Topological Systems with Anyonic Symmetries

Jeffrey Teo University of Illinois Urbana-Champaign

November 08, 2013

PIRSA:13110078

Twist defects are point-like objects that support robust non-local storage of quantum information and non-abelian unitary operations. Unlike quantum deconfined anyonic excitations, they rely on symmetry rather than a non-abelian topological order. Zero energy Majorana bound states can arise at lattice defects, such as disclinations and dislocations, in a topological crystalline superconductor. More general parafermion bound state can appear as twist defects in a topological phase with an anyonic symmetry, such as a bilayer fractional quantum Hall state and the Kitaev toric code. They are however fundamentally different from quantum anyonic excitations in a true topological phase. This is demonstrated by their unconventional exchange and braiding behavior, which is characterized by a modified spin statistics theorem and modular invariance.
Quantum and Classical Anomalies

Michael Stone University of Illinois Urbana-Champaign

November 08, 2013

PIRSA:13110077

I will begin reviewing the Callan-Harvey mechanism of anomaly inflow with particular focus on topological edge states and show how the inflow picture naturally converts the non-covariant "consistent" gauge anomaly of Bardeen and Zumino to the more physical "covariant" anomaly. I will then discuss some recent derivations of the covariant form of the gauge anomaly from classical phase space flows.
Majorana State Properties in Semiconductor and Oxide Superconducting Quantum Wires

Allan MacDonald The University of Texas at Austin

November 08, 2013

PIRSA:13110076

When proximity coupled to s-wave superconductors, quantum wires can support effective p-wave superconductivity under appropriate circumstances. The p-wave state has Majorana states at the wire ends which can store quantum information. I will discuss some properties of Majorana states formed in oxide and semiconductor quantum wires, including superconducting state phase diagrams as a function of spin-orbit coupling strength, Fermi energy, and external magnetic field strength, and Majorana exchange properties.
Discussion

Eduardo Fradkin University of Illinois Urbana-Champaign

November 07, 2013

PIRSA:13110075
Quantum quenches & holography

Robert Myers Perimeter Institute for Theoretical Physics

November 07, 2013

PIRSA:13110074

We employ holographic techniques to study quantum quenches at finite temperature, where the quenches involve varying the coupling of the boundary theory to a relevant operator with an arbitrary conformal dimension. The evolution of the system is studied by evaluating the expectation value of the quenched operator and the stress tensor throughout the process. The time dependence of the new coupling is characterized by a fixed timescale and the response of the observables depends on the ratio of the this timescale to the initial temperature. The observables exhibit universal scaling behaviours when the transitions are either fast or slow, i.e., when this ratio is very small or very large. For fast quenches, we uncover a universal scaling behaviour in the response of the system, which depends only on the conformal dimension of the quenched operator in the vicinity of the ultraviolet fixed point of the theory.
Many-body localization: entanglement, emergent conservation laws, and the structure of eigenstates

Dmitry Abanin

November 07, 2013

PIRSA:13110073

Title	Speaker(s)	Date	Talk Type	Info link
Modelling Materials Microstructure Across Scales using Phase Field Methods	Nikolas Provatas	2013-12-05	Conference	View details
Building Colloidal Crystals in Anisotropic Media	Colin Denniston	2013-12-05	Conference	View details
Transition Pathways Connecting Stable and Metastable Phases	An-Chang Shi	2013-12-05	Conference	View details
Monte Carlo Field-Theoretic Simulations Applied to Block Copolymer Melts	Mark Matsen	2013-12-05	Conference	View details
O Topology	Randall Kamien	2013-12-05	Conference	View details
Discussion	Xiao-Gang Wen	2013-11-08	Conference	View details
Twist Defects in Topological Systems with Anyonic Symmetries	Jeffrey Teo	2013-11-08	Conference	View details
Quantum and Classical Anomalies	Michael Stone	2013-11-08	Conference	View details
Majorana State Properties in Semiconductor and Oxide Superconducting Quantum Wires	Allan MacDonald	2013-11-08	Conference	View details
Discussion	Eduardo Fradkin	2013-11-07	Conference	View details
Quantum quenches & holography	Robert Myers	2013-11-07	Conference	View details
Many-body localization: entanglement, emergent conservation laws, and the structure of eigenstates	Dmitry Abanin	2013-11-07	Conference	View details

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Format results

Modelling Materials Microstructure Across Scales using Phase Field Methods

Building Colloidal Crystals in Anisotropic Media

Transition Pathways Connecting Stable and Metastable Phases

Monte Carlo Field-Theoretic Simulations Applied to Block Copolymer Melts

O Topology

Discussion

Twist Defects in Topological Systems with Anyonic Symmetries

Quantum and Classical Anomalies

Majorana State Properties in Semiconductor and Oxide Superconducting Quantum Wires

Discussion

Quantum quenches & holography

Many-body localization: entanglement, emergent conservation laws, and the structure of eigenstates

Modelling Materials Microstructure Across Scales using Phase Field Methods

Building Colloidal Crystals in Anisotropic Media

Transition Pathways Connecting Stable and Metastable Phases

Monte Carlo Field-Theoretic Simulations Applied to Block Copolymer Melts

O Topology

Discussion

Twist Defects in Topological Systems with Anyonic Symmetries

Quantum and Classical Anomalies

Majorana State Properties in Semiconductor and Oxide Superconducting Quantum Wires

Discussion

Quantum quenches & holography

Many-body localization: entanglement, emergent conservation laws, and the structure of eigenstates