Condensed Matter

Boundaries and defects play central roles in quantum field theory (QFT) both as means to make contact with nature and as tools to constrain and understand QFT itself. Boundaries in QFT can be used to model impurities and also the finite extent of sample sizes while interfaces allow for different phases of matter to interact in a controllable way. More formally these structures shed light on the structure of QFT by providing new examples of dualities and renormalization group flows.  Broadly speaking this meeting will focus on three areas: 1) formal and applied aspects of boundary and defect conformal field theory from anomalies and c-theorems to topological insulators 2) supersymmetry and duality from exact computations of new observables to the construction of new theories and 3) QFT in curved space and gravity from holographic computations of entanglement entropy to ideas in quantum information theory. Registration for this event is now open.

Machine learning techniques are rapidly being adopted into the field of quantum many-body physics including condensed matter theory experiment and quantum information science.  The steady increase in data being produced by highly-controlled quantum experiments brings the potential of machine learning algorithms to the forefront of scientific advancement.  Particularly exciting is the prospect of using machine learning for the discovery and design of quantum materials devices and computers.  In order to make progress the field must address a number of fundamental questions related to the challenges of studying many-body quantum mechanics using classical computing algorithms and hardware. The goal of this conference is to bring together experts in computational physics machine learning and quantum information to make headway on a number of related topics including: Data-drive quantum state reconstruction Machine learning strategies for quantum error correction Neural-network based wavefunctions Near-term prospects for data from quantum devices Machine learning for quantum algorithm discovery Registration for this event is now closed

On Thursday June 13 the Institute for Quantum Computing (IQC) and Perimeter Institute for Theoretical Physics (PI) will participate in the one-day Many-Body States and Dynamics Workshop II. The goal of the workshop is to describe ongoing efforts to experimentally realize quantum many-body states and dynamics and discuss interesting classes of states and dynamics that could be targeted. Experimentalists working on several platforms (such as photons atom and ion traps superconducting qubits exciton-polaritons or NMR) and theoreticians specialized in many-body theory (entanglement topological order gauge theories criticality chaos error correction holography) and numerical simulations (exact diagonalization Monte Carlo DMRG tensor networks) will meet for a morning workshop to identify and discuss common interests.

This third workshop of the Perimeter Institute series Emergence and Entanglement will center around four major frontiers in quantum matter research:  (i) topological matter including recently discovered phases in three dimensions and new routes toward experimental realization (ii) critical states of matter especially interacting CFTs in 2+1 dimensions and dualities (iii) state-of-the-art numerical approaches to tackle such many-body problems (e.g. DMRG MERA Monte Carlo) and (iv) quantum dynamics and thermalization.

Throughout the history of quantum field theory there has been a rich cross-pollination between high energy and condensed matter physics. From the theory of renormalization to the consequences of spontaneous symmetry breaking this interaction has been an incredibly fruitful one. In the last decade there has been a strong resurgence of interest in condensed matter systems in the high energy theoretical physics community. Taking advantage of developments in conformal field theories the conformal bootstrap gauge/gravity and other type of dualities as well as effective field theory techniques high energy theorists with all kinds of specialist backgrounds are thinking about the diverse behavior exhibited in low energy physical systems. Recent developments also employed quantum field theory ideas to improve our understanding of condensed and quantum matter systems as for example Femi liquids strange metals or the behavior of topological defects in ultra cold atom gases. For certain questions such approaches present relevant advantages with respect to more traditional techniques. Moreover in recent years the interplay between high energy and condensed matter physics found new fuel in the search for light dark matter. Indeed theoretical analyses have recently shifted the attention towards model for sub-GeV dark matter. The condensed matter community has played a crucial role in the design of possible new materials and detectors that could allow the observation of such particles. The aim of this workshop is to bring together like-minded high energy theorists with appropriate condensed matter theorists and experimentalists to tackle some of the most interesting problems in modern physics. The format has been designed to allow for plenty of time for open discussion and interaction between the participants. This will reinvigorate existing collaborations as well as create new fruitful ones.

The Kitaev quantum double models are a family of topologically ordered spin models originally proposed to exploit the novel condensed matter phenomenology of topological phases for fault-tolerant quantum computation. Their physics is inherited from topological quantum field theories, while their underlying mathematical structure is based on a class of Hopf algebras. This structure is also seen across diverse fields of physics, and so allows connections to be made between the Kitaev models and topics as varied as quantum gauge theory and modified strong complementarity. This workshop will explore this shared mathematical structure and in so doing develop the connections between the fields of mathematical physics, quantum gravity, quantum information, condensed matter and quantum foundations.