Condensed Matter

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PSI 2014/2015 - Condensed Matter - Lecture 7

Marcel Franz University of British Columbia
November 18, 2014

PIRSA:14110033
Condensed Matter
PSI 2014/2015 - Condensed Matter - Lecture 6

Marcel Franz University of British Columbia
November 17, 2014

PIRSA:14110032
Condensed Matter
PSI 2014/2015 - Condensed Matter - Lecture 5

Marcel Franz University of British Columbia
November 14, 2014

PIRSA:14110029
Condensed Matter
PSI 2014/2015 - Condensed Matter - Lecture 4

Marcel Franz University of British Columbia
November 13, 2014

PIRSA:14110028
Condensed Matter
PSI 2014/2015 - Condensed Matter - Lecture 3

Marcel Franz University of British Columbia
November 12, 2014

PIRSA:14110027
Condensed Matter
PSI 2014/2015 - Condensed Matter - Lecture 2

Marcel Franz University of British Columbia
November 11, 2014

PIRSA:14110026
Condensed Matter
PSI 2014/2015 - Condensed Matter - Lecture 1

Marcel Franz University of British Columbia
November 10, 2014

PIRSA:14110025
Condensed Matter

Physics
Spin-charge scattering in Luttinger Liquids

Alex Levchenko Michigan State University (MSU)
November 04, 2014

PIRSA:14110096
Condensed Matter
Numerical Study of a Bosonic Topological Insulator in Three Dimensions

Scott Geraedts California Institute of Technology
October 21, 2014

PIRSA:14100113
Condensed Matter
Bulk Entanglement Spectrum: From Topological States to Quantum Criticality

Timothy Hsieh Perimeter Institute for Theoretical Physics
October 14, 2014

PIRSA:14100075
Condensed Matter
Quantum Entanglement and Superconductivity

Subir Sachdev Harvard University
October 01, 2014

PIRSA:14100080
Condensed Matter
Irreversibility and Entanglement Spectrum Statistics in Quantum Circuits

Eduardo Mucciolo University of Central Florida
September 30, 2014

PIRSA:14090028
Condensed Matter

PSI 2014/2015 - Condensed Matter - Lecture 7

Marcel Franz University of British Columbia
November 18, 2014

PIRSA:14110033
Condensed Matter
PSI 2014/2015 - Condensed Matter - Lecture 6

Marcel Franz University of British Columbia
November 17, 2014

PIRSA:14110032
Condensed Matter
PSI 2014/2015 - Condensed Matter - Lecture 5

Marcel Franz University of British Columbia
November 14, 2014

PIRSA:14110029
Condensed Matter
PSI 2014/2015 - Condensed Matter - Lecture 4

Marcel Franz University of British Columbia
November 13, 2014

PIRSA:14110028
Condensed Matter
PSI 2014/2015 - Condensed Matter - Lecture 3

Marcel Franz University of British Columbia
November 12, 2014

PIRSA:14110027
Condensed Matter
PSI 2014/2015 - Condensed Matter - Lecture 2

Marcel Franz University of British Columbia
November 11, 2014

PIRSA:14110026
Condensed Matter
PSI 2014/2015 - Condensed Matter - Lecture 1

Marcel Franz University of British Columbia
November 10, 2014

PIRSA:14110025
Condensed Matter

Physics
Spin-charge scattering in Luttinger Liquids

Alex Levchenko Michigan State University (MSU)
November 04, 2014

PIRSA:14110096
Condensed Matter
I will discuss the violation of spin-charge separation in generic Luttinger liquids and investigate its effect on the relaxation, thermal and electrical transport of genuine spin-1/2 electron liquids in ballistic quantum wires. We will identify basic scattering processes compatible with the symmetry of the problem and conservation laws that lead to the decay of plasmons into the spin modes and also discuss Brownian backscattering of spin excitations. I will present a closed set of coupled kinetic equations for the spin-charge excitations and solve the problem of electrical and thermal conductance of interacting electrons for an arbitrary relation between the quantum wire length and spin-charge thermalization length.
Numerical Study of a Bosonic Topological Insulator in Three Dimensions

Scott Geraedts California Institute of Technology
October 21, 2014

PIRSA:14100113
Condensed Matter
We construct a model which realizes a (3+1)-dimensional symmetry-protected topological phase of bosons with U(1) charge conservation and time reversal symmetry, envisioned by A. Vishwanath and T. Senthil [PRX 4 011016]. Our model works by introducing an additional spin degree of freedom, and binding its hedgehogs to a species of charged bosons. We study the model using Monte Carlo and determine its bulk phase diagram; the phase where the bound states of hedgehogs and charges condense is the topological phase, and we demonstrate this by observing a Witten effect. We also study the surface phase diagram on a (2+1)-dimensional boundary between the topological and trivial insulators. We find a number of exotic phases on the surface, including exotic superfluids, a phase with a Hall conductivity quantized to half the value possible in 2D, and a phase with intrinsic topological order. We also find a new bulk phase with intrinsic topological order.
Bulk Entanglement Spectrum: From Topological States to Quantum Criticality

Timothy Hsieh Perimeter Institute for Theoretical Physics
October 14, 2014

PIRSA:14100075
Condensed Matter
A quantum phase transition is usually achieved by tuning physical parameters in a Hamiltonian at zero temperature. Here, we demonstrate that the ground state of a topological phase itself encodes critical properties of its transition to a trivial phase. To extract this information, we introduce a partition of the system into two subsystems both of which extend throughout the bulk in all directions. The resulting bulk entanglement spectrum (BES) has a low-lying part that resembles the excitation spectrum of a bulk Hamiltonian, which allows us to probe a topological phase transition from a single wavefunction by tuning either the geometry of the partition or the entanglement temperature. As an example, this remarkable correspondence between topological phase transition and entanglement criticality is rigorously established for integer quantum Hall states. We also implement BES using tensor networks, derive the universality classes of topological phase transitions from the spin-1 chain Haldane phase, and demonstrate that the AKLT wavefunction (and its generalizations) remarkably contains critical six-vertex (and in general eight-vertex) models within it.
Quantum Entanglement and Superconductivity

Subir Sachdev Harvard University
October 01, 2014

PIRSA:14100080
Condensed Matter
Einstein called it “spooky action at a distance.” Entanglement is a counterintuitive feature of quantum theory by which two particles are deeply correlated even when separated by vast distances, such that a measurement of one particle instantaneously determines the state of another. Remarkably, quantum entanglement can also happen en masse, determining the macroscopic properties of many electrons in certain crystals. These newly discovered states of matter could lead to practical high-temperature superconductors, which promise tremendous advances in technologies spanning medicine, clean energy, transportation, and more. Dr. Subir Sachdev, a leading researcher in the field, will explain new experiments in high-temperature superconductivity, and even do a live demonstration of superconducting levitation. He will even explore the unexpected new connections between these earthbound experiments and the strange quantum behaviour of black holes.
Irreversibility and Entanglement Spectrum Statistics in Quantum Circuits

Eduardo Mucciolo University of Central Florida
September 30, 2014

PIRSA:14090028
Condensed Matter
We show that for a system evolving unitarily under a stochastic quantum circuit, the notions of irreversibility, universality of computation, and entanglement are closely related. As the state of the system evolves from an initial product state, it becomes increasingly entangled until entanglement reaches a maximum. We define irreversibility as the failure to find a circuit that disentangles a maximally entangled state. We show that irreversibility occurs when maximally entangled states are generated with a quantum circuit formed by gates from a universal quantum computation set. We find that irreversibility is also associated to a Wigner-Dyson statistics in the fluctuations of spacings between adjacent eigenvalues of the system’s reduced density matrix. In contrast, when the system is evolved with a non-universal set of gates, the statistics of the entanglement spacing deviates from Wigner-Dyson and the disentangling algorithm succeeds. We discuss how these findings open a new way to characterize non-integrability in quantum systems.

Title	Speaker(s)	Date	Talk Type	Info link
PSI 2014/2015 - Condensed Matter - Lecture 7	Marcel Franz	2014-11-18	Course	View details
PSI 2014/2015 - Condensed Matter - Lecture 6	Marcel Franz	2014-11-17	Course	View details
PSI 2014/2015 - Condensed Matter - Lecture 5	Marcel Franz	2014-11-14	Course	View details
PSI 2014/2015 - Condensed Matter - Lecture 4	Marcel Franz	2014-11-13	Course	View details
PSI 2014/2015 - Condensed Matter - Lecture 3	Marcel Franz	2014-11-12	Course	View details
PSI 2014/2015 - Condensed Matter - Lecture 2	Marcel Franz	2014-11-11	Course	View details
PSI 2014/2015 - Condensed Matter - Lecture 1	Marcel Franz	2014-11-10	Course	View details
Spin-charge scattering in Luttinger Liquids	Alex Levchenko	2014-11-04	Scientific Series	View details
Numerical Study of a Bosonic Topological Insulator in Three Dimensions	Scott Geraedts	2014-10-21	Scientific Series	View details
Bulk Entanglement Spectrum: From Topological States to Quantum Criticality	Timothy Hsieh	2014-10-14	Scientific Series	View details
Quantum Entanglement and Superconductivity	Subir Sachdev	2014-10-01	Public Lectures	View details
Irreversibility and Entanglement Spectrum Statistics in Quantum Circuits	Eduardo Mucciolo	2014-09-30	Scientific Series	View details

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PSI 2014/2015 - Condensed Matter - Lecture 7

PSI 2014/2015 - Condensed Matter - Lecture 6

PSI 2014/2015 - Condensed Matter - Lecture 5

PSI 2014/2015 - Condensed Matter - Lecture 4

PSI 2014/2015 - Condensed Matter - Lecture 3

PSI 2014/2015 - Condensed Matter - Lecture 2

PSI 2014/2015 - Condensed Matter - Lecture 1

Spin-charge scattering in Luttinger Liquids

Numerical Study of a Bosonic Topological Insulator in Three Dimensions

Bulk Entanglement Spectrum: From Topological States to Quantum Criticality

Quantum Entanglement and Superconductivity

Irreversibility and Entanglement Spectrum Statistics in Quantum Circuits

PSI 2014/2015 - Condensed Matter - Lecture 7

PSI 2014/2015 - Condensed Matter - Lecture 6

PSI 2014/2015 - Condensed Matter - Lecture 5

PSI 2014/2015 - Condensed Matter - Lecture 4

PSI 2014/2015 - Condensed Matter - Lecture 3

PSI 2014/2015 - Condensed Matter - Lecture 2

PSI 2014/2015 - Condensed Matter - Lecture 1

Spin-charge scattering in Luttinger Liquids

Numerical Study of a Bosonic Topological Insulator in Three Dimensions

Bulk Entanglement Spectrum: From Topological States to Quantum Criticality

Quantum Entanglement and Superconductivity

Irreversibility and Entanglement Spectrum Statistics in Quantum Circuits