Format results

Talk

PSI 2016/2017  Condensed Matter (Review)  Lecture 12
Guifre Vidal Alphabet (United States)

PSI 2016/2017  Condensed Matter (Review)  Lecture 11
Guifre Vidal Alphabet (United States)

PSI 2016/2017  Condensed Matter (Review)  Lecture 10
Guifre Vidal Alphabet (United States)

PSI 2016/2017  Condensed Matter (Review)  Lecture 9
Guifre Vidal Alphabet (United States)

PSI 2016/2017  Condensed Matter (Review)  Lecture 8
Guifre Vidal Alphabet (United States)

PSI 2016/2017  Condensed Matter (Review)  Lecture 7
Guifre Vidal Alphabet (United States)

PSI 2016/2017  Condensed Matter (Review)  Lecture 6
Guifre Vidal Alphabet (United States)

PSI 2016/2017  Condensed Matter (Review)  Lecture 5
Guifre Vidal Alphabet (United States)


Talk


Solitons and SpinCharge Correlations in Strongly Interacting Fermi Gases
Martin Zwierlein Massachusetts Institute of Technology (MIT)

Hierarchical growth of entangled states
John McGreevy University of California, San Diego

Scaling geometries and DC conductivities
Sera Cremonini LeHigh University

Viscous Electron Fluids: HigherThanBallistic Conduction Negative Nonlocal Resistance and Vortices
Leonid Levitov Massachusetts Institute of Technology (MIT)  Department of Physics

Universal Diffusion and the Butterfly Effect
Michael Blake Massachusetts Institute of Technology (MIT)

ParticleVortex duality and Topological Quantum Matter
Jeff Murugan Institute for Advanced Study (IAS)  School of Natural Sciences (SNS)



Talk


Comparing Classical and Quantum Methods for Supervised Machine Learning
Ashish Kapoor Microsoft Corporation

Classification on a quantum computer: Linear regression and ensemble methods
Maria Schuld University of KwaZuluNatal

Rejection and Particle Filtering for Hamiltonian Learning
Christopher Granade Dual Space Solutions, LLC



Physical approaches to the extraction of relevant information
David Schwab Northwestern University

Learning with QuantumInspired Tensor Networks
Miles Stoudenmire Flatiron Institute


Talk


Superconductivity and Charge Density Waves in the Clean 2D Limit
Adam Tsen Institute for Quantum Computing (IQC)

Honeycomb lattice quantum magnets with strong spinorbit coupling
YoungJune Kim University of Toronto



Stochastic Resonance Magnetic Force Microscopy: A Technique for Nanoscale Imaging of Vortex Dynamics
Raffi Budakian Institute for Quantum Computing (IQC)

Spin Slush in an Extended Spin Ice Model
Jeff Rau University of Waterloo

Universal Dynamic Magnetism in the Ytterbium Pyrochlores
Alannah Hallas McMaster University



NonHermitian operators in manybody physics
Jacob Barnett University of the Basque Country

Replica topological order in quantum mixed states and quantum error correction
Roger Mong University of Pittsburgh

Quantum Spin Liquid Oasis in Desert States of Unfrustrated Spin Models: Mirage ?
Baskaran Ganapathy Institute of Mathematical Sciences

Machine Learning Lecture
Damian Pope Perimeter Institute for Theoretical Physics



The Stability of Gapped Quantum Matter and ErrorCorrection with Adiabatic Noise  VIRTUAL
Ali Lavasani University of California, Santa Barbara

PSI 2016/2017  Condensed Matter Review (Vidal)
PSI 2016/2017  Condensed Matter Review (Vidal) 
Low Energy Challenges for High Energy Physicists II
Low Energy Challenges for High Energy Physicists II


4 Corners Southwest Ontario Condensed Matter Symposium
4 Corners Southwest Ontario Condensed Matter Symposium 
Computational Phase Transitions in TwoDimensional Antiferromagnetic Melting
A computational phase transition in a classical or quantum system is a nonanalytic change in behavior of an order parameter which can only be observed with the assistance of a nontrivial classical computation. Such phase transitions, and the computational observables which detect them, play a crucial role in the optimal decoding of quantum errorcorrecting codes and in the scalable detection of measurementinduced phenomena. We show that computational phase transitions and observables can also provide important physical insight on the phase diagram of a classical statistical physics system, specifically in the context of the dislocationmediated melting of a twodimensional antiferromagnetic (AF) crystal. In the solid phase, elementary dislocations disrupt the bipartiteness of the underlying square lattice, and as a result, pairs of dislocations are linearly confined by stringlike AF domain walls. It has previously been argued that a novel AF tetratic phase can arise when double dislocations proliferate while elementary dislocations remain bound. We will argue that, although there is no thermodynamic phase transition separating the AF and paramagnetic (PM) tetratic phases, it is possible to algorithmically construct a nonlocal order parameter which distinguishes the AF and PM tetratic regimes and undergoes a continuous computational phase transition. We discuss both algorithmdependent and "intrinsic" algorithmindependent computational phase transitions in this setting, the latter of which includes a transition in one's ability to consistently sort atoms into two sublattices to construct a welldefined staggered magnetization.

NonHermitian operators in manybody physics
Jacob Barnett University of the Basque Country
NonHermitian Hamiltonians are a compulsory aspect of the linear dynamical systems that model many physical phenomena, such as those in electrical circuits, open quantum systems, and optics. Additionally, a representation of the quantum theory of closed systems with nonHermitian observables possessing unbroken PTsymmetry is welldefined. In this talk, I will secondquantize nonHermitian quantum theories with paraFermionic statistics. To do this, I will introduce an efficient method to find conserved quantities when the Hamiltonian is free or translationally invariant. Using a specific nonHermitian perturbation of the SuSchriefferHeeger (SSH ) model, a prototypical topological insulator, I examine how PTsymmetry breaking occurs at the topological phase transition. Finally, I show that although finitedimensional PTsymmetric quantum theories generalize the tensor product model of locality, they never permit Bell inequality violations beyond what is possible in the Hermitian quantum tensor product model. 
Replica topological order in quantum mixed states and quantum error correction
Roger Mong University of Pittsburgh
Topological phases of matter offer a promising platform for quantum computation and quantum error correction. Nevertheless, unlike its counterpart in pure states, descriptions of topological order in mixed states remain relatively underexplored. We will give various definitions for replica topological order in mixed states. Similar to the replica trick, our definitions also involve n copies of density matrix of the mixed state. Within this framework, we categorize topological orders in mixed states as either quantum, classical, or trivial, depending on the type of information they encode.
For the case of the toric code model in the presence of decoherence, we associate for each phase a quantum channel and describes the structure of the code space. We show that in the quantumtopological phase, there exists a postselectionbased error correction protocol that recovers the quantum information, while in the classicaltopological phase, the quantum information has decohere and cannot be fully recovered. We accomplish this by describing the mixed state as a projected entangled pairs state (PEPS) and identifying the symmetryprotected topological order of its boundary state to the bulk topology.


Quantum Spin Liquid Oasis in Desert States of Unfrustrated Spin Models: Mirage ?
Baskaran Ganapathy Institute of Mathematical Sciences
Hilbert spaces are incomprehensibly vast and rich. Model Hamiltonians are space ships. They could take us to new worlds, such as cold \textit{spin liquid oasis} in hot regions in Hilbert space deserts. Exact decomposition of isotropic Heisenberg Hamiltonian on a Honeycomb lattice into a sum of 3 noncommuting (permuted) Kitaev Hamiltonians, helps us build a degenerate \textit{manifold of metastable flux free Kitaev spin liquid vacua} and vector Fermionic (Goldstone like) collective modes. Our method, \textit{symmetric decomposition of Hamiltonians}, will help design exotic metastable quantum scars and exotic quasi particles, in nonexotic real systems.
G. Baskaran, arXiv:2309.07119

Machine Learning Lecture
Damian Pope Perimeter Institute for Theoretical Physics



The Stability of Gapped Quantum Matter and ErrorCorrection with Adiabatic Noise  VIRTUAL
Ali Lavasani University of California, Santa Barbara
The code space of a quantum errorcorrecting code can often be identified with the degenerate groundspace within a gapped phase of quantum matter. We argue that the stability of such a phase is directly related to a set of coherent error processes against which this quantum errorcorrecting code (QECC) is robust: such a quantum code can recover from adiabatic noise channels, corresponding to random adiabatic drift of code states through the phase, with asymptotically perfect fidelity in the thermodynamic limit, as long as this adiabatic evolution keeps states sufficiently "close" to the initial groundspace. We further argue that when specific decoders  such as minimumweight perfect matching  are applied to recover this information, an errorcorrecting threshold is generically encountered within the gapped phase. In cases where the adiabatic evolution is known, we explicitly show examples in which quantum information can be recovered by using stabilizer measurements and Pauli feedback, even up to a phase boundary, though the resulting decoding transitions are in different universality classes from the optimal decoding transitions in the presence of incoherent Pauli noise. This provides examples where nonlocal, coherent noise effectively decoheres in the presence of syndrome measurements in a stabilizer QECC.
