Talks

11953 - 11964 of 20132 Results

On null singularities in general relativity

Mihalis Dafermos Princeton University

February 13, 2014

PIRSA:14020133

General Relativity & Quantum Cosmology
Gauging symmetry of 2D topological phases

Zhenghan Wang Microsoft Corporation

February 13, 2014

PIRSA:14020125
13/14 PSI - Cosmology Review - Lecture 12

Latham Boyle University of Edinburgh

February 13, 2014

PIRSA:14020101
Incoherent metals

Brian Swingle Brandeis University

February 13, 2014

PIRSA:14020124
13/14 PSI - String Theory Review - Lecture 13

Davide Gaiotto Perimeter Institute for Theoretical Physics

February 13, 2014

PIRSA:14020033
Interacting electronic topological insulators in three dimensions

Senthil Todadri Massachusetts Institute of Technology (MIT) - Department of Physics

February 13, 2014

PIRSA:14020123
13/14 PSI - Condensed Matter Review - Lecture 13

Alioscia Hamma University of Naples Federico II

February 13, 2014

PIRSA:14020106
Chiral spin liquid and emergent anyons in a Kagome lattice Mott insulator

Guifre Vidal Alphabet (United States)

Lukasz Cincio Los Alamos National Laboratory

February 13, 2014

PIRSA:14020122
Applications of Information Theory in Direct Sum and Direct Product Problems

February 12, 2014

PIRSA:14020142

Quantum Physics
Quantum Tapestries

Matthew Fisher University of California, Santa Barbara

February 12, 2014

PIRSA:14020121
A symmetry-respecting topologically-ordered surface phase of 3d electron topological insulators.

Max Metlitski Massachusetts Institute of Technology (MIT) - Department of Physics

February 12, 2014

PIRSA:14020120
13/14 PSI - Cosmology Review - Lecture 11

Latham Boyle University of Edinburgh

February 12, 2014

PIRSA:14020021

On null singularities in general relativity

Mihalis Dafermos Princeton University

February 13, 2014

PIRSA:14020133

General Relativity & Quantum Cosmology

This talk will discuss the formation, structure and interaction of null singularities for
the Einstein equations, as well as what this all means for the singular boundary
of generic space times within black hole regions.
Gauging symmetry of 2D topological phases

Zhenghan Wang Microsoft Corporation

February 13, 2014

PIRSA:14020125

I will discuss the mathematical framework for gauging a local unitary finite group symmetry of a 2D topological phase of matter.
13/14 PSI - Cosmology Review - Lecture 12

Latham Boyle University of Edinburgh

February 13, 2014

PIRSA:14020101
Incoherent metals

Brian Swingle Brandeis University

February 13, 2014

PIRSA:14020124

I'll talk about some work in progress concerning the topic of metals which have no coherent quasiparticles. In particular, I'll compare and contrast the ubiquitous near horizon AdS2 region appearing in holographic models with a phase of matter called the spin incoherent luttinger liquid. By analyzing the structure of entanglement and correlations, we will find many similarities between these two states of matter. An interpretation of some incoherent metals as describing intermediate scale renormalization group fixed poins with an infinite number of relevant directions will also be discussed.
13/14 PSI - String Theory Review - Lecture 13

Davide Gaiotto Perimeter Institute for Theoretical Physics

February 13, 2014

PIRSA:14020033
Interacting electronic topological insulators in three dimensions

Senthil Todadri Massachusetts Institute of Technology (MIT) - Department of Physics

February 13, 2014

PIRSA:14020123

I will review recent progress in describing interacting electronic topological insulators/superconductors in three dimensions. The focus will be on Symmetry Protected Topological (SPT) phases of electronic systems with charge conservation and time reversal. I will argue that the well known Z2 classification of free fermion insulators with this important symmetry generalizes to a Z2^3 classification in the presence of interactions. I will describe the experimental fingerprints and other physical properties of these states. If time permits, I will describe results on the classification and properties of 3d electronic SPT states with various other physically relevant symmetries.
13/14 PSI - Condensed Matter Review - Lecture 13

Alioscia Hamma University of Naples Federico II

February 13, 2014

PIRSA:14020106
Chiral spin liquid and emergent anyons in a Kagome lattice Mott insulator

Guifre Vidal Alphabet (United States)

Lukasz Cincio Los Alamos National Laboratory

February 13, 2014

PIRSA:14020122

Topological phases in frustrated quantum spin systems have fascinated researchers for decades. One of the earliest proposals for such a phase was the chiral spin liquid put forward by Kalmeyer and Laughlin in 1987 as the bosonic analogue of the fractional quantum Hall effect. Elusive for many years, recent times have finally seen a number of models that realize this phase. However, these models are somewhat artificial and unlikely to be found in realistic materials.
Here, we take an important step towards the goal of finding a chiral spin liquid in nature by examining a physically motivated model for a Mott insulator on the Kagome lattice with broken time-reversal symmetry. We first provide a theoretical justification for the emergent chiral spin liquid phase in terms of a network model perspective. We then present an unambiguous numerical identification and characterization of the universal topological properties of the phase, including ground state degeneracy, edge physics, and anyonic bulk excitations, by using a variety of powerful numerical probes, including the entanglement spectrum and modular transformations.
Applications of Information Theory in Direct Sum and Direct Product Problems

February 12, 2014

PIRSA:14020142

Quantum Physics

A fundamental question in complexity theory is how much resource is needed to solve k independent instances of a problem compared to the resource required to solve one instance. Suppose solving one instance of a problem with probability of correctness p, we require c units of some resource in a given model of computation. A direct sum theorem states that in order to compute k independent instances of a problem, it requires k times units of the resource needed to compute one instance. A strong direct product theorem states that, with o(k • c) units of the resource, one can only compute all the k instances correctly with probability exponentially small in k. In this talk, I am going to present some of recent progress on direct sum and direct product theorems in the model of communication complexity and two-prover one-round games with information-theoretic approach. The talk is based on parts of my doctoral work.
Quantum Tapestries

Matthew Fisher University of California, Santa Barbara

February 12, 2014

PIRSA:14020121

Within each of nature's crystals is an exotic quantum world of electrons weaving to and fro. Each crystal has it's own unique tapestry, as varied as the crystals themselves. In some crystals, the electrons weave an orderly quilt. Within others, the electrons are seemingly entwined in an entangled web of quantum motion. In this talk, I will describe the ongoing efforts to disentangle even nature's most intricate quantum embroidery. Cutting-edge quantum many-body simulations together with recent ideas from quantum information theory, such as entanglement entropy, are enabling a coherent picture to emerge.
A symmetry-respecting topologically-ordered surface phase of 3d electron topological insulators.

Max Metlitski Massachusetts Institute of Technology (MIT) - Department of Physics

February 12, 2014

PIRSA:14020120

A 3d electron topological insulator (ETI) is a phase of matter protected by particle-number conservation and time-reversal symmetry. It was previously believed that the surface of an ETI must be gapless unless one of these symmetries is broken. A well-known symmetry-preserving, gapless surface termination of an ETI supports an odd number of Dirac cones. In this talk, I will show that in the presence of strong interactions, an ETI surface can actually be gapped and symmetry preserving, at the cost of carrying an intrinsic two-dimensional topological order. I will argue that such a topologically ordered phase can be obtained from the surface superconductor by proliferating the flux 2hc/e vortex. The resulting topological order consists of two sectors: a Moore-Read sector, which supports non-Abelian charge e/4 anyons, and an Abelian anti-semion sector, which is electrically neutral. The time-reversal and particle number symmetries are realized in this surface phase in an "anomalous" way: one which is impossible in a strictly 2d system. If time permits, I will discuss related results on topologically ordered surface phases of 3d topological superconductors.
13/14 PSI - Cosmology Review - Lecture 11

Latham Boyle University of Edinburgh

February 12, 2014

PIRSA:14020021

Title	Date	Collection	Type	Info
On null singularities in general relativity	2014‑02‑13	Strong Gravity	Scientific Series	View details
Gauging symmetry of 2D topological phases	2014‑02‑13	Emergence in Complex Systems	Conference	View details
13/14 PSI - Cosmology Review - Lecture 12	2014‑02‑13	13/14 PSI - Cosmology Review	Course	View details
Incoherent metals	2014‑02‑13	Emergence in Complex Systems	Conference	View details
13/14 PSI - String Theory Review - Lecture 13	2014‑02‑13	13/14 PSI - String Theory Review	Course	View details
Interacting electronic topological insulators in three dimensions	2014‑02‑13	Emergence in Complex Systems	Conference	View details
13/14 PSI - Condensed Matter Review - Lecture 13	2014‑02‑13	13/14 PSI - Condensed Matter Review	Course	View details
Chiral spin liquid and emergent anyons in a Kagome lattice Mott insulator	2014‑02‑13	Emergence in Complex Systems	Conference	View details
Applications of Information Theory in Direct Sum and Direct Product Problems	2014‑02‑12	Perimeter Institute Quantum Discussions	Scientific Series	View details
Quantum Tapestries	2014‑02‑12	Emergence in Complex Systems	Conference	View details
A symmetry-respecting topologically-ordered surface phase of 3d electron topological insulators.	2014‑02‑12	Emergence in Complex Systems	Conference	View details
13/14 PSI - Cosmology Review - Lecture 11	2014‑02‑12	13/14 PSI - Cosmology Review	Course	View details

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Format results

On null singularities in general relativity

Gauging symmetry of 2D topological phases

13/14 PSI - Cosmology Review - Lecture 12

Incoherent metals

13/14 PSI - String Theory Review - Lecture 13

Interacting electronic topological insulators in three dimensions

13/14 PSI - Condensed Matter Review - Lecture 13

Chiral spin liquid and emergent anyons in a Kagome lattice Mott insulator

Applications of Information Theory in Direct Sum and Direct Product Problems

Quantum Tapestries

A symmetry-respecting topologically-ordered surface phase of 3d electron topological insulators.

13/14 PSI - Cosmology Review - Lecture 11

On null singularities in general relativity

Gauging symmetry of 2D topological phases

13/14 PSI - Cosmology Review - Lecture 12

Incoherent metals

13/14 PSI - String Theory Review - Lecture 13

Interacting electronic topological insulators in three dimensions

13/14 PSI - Condensed Matter Review - Lecture 13

Chiral spin liquid and emergent anyons in a Kagome lattice Mott insulator

Applications of Information Theory in Direct Sum and Direct Product Problems

Quantum Tapestries

A symmetry-respecting topologically-ordered surface phase of 3d electron topological insulators.

13/14 PSI - Cosmology Review - Lecture 11