Quantum Information

There has been a surge of interest in indefinite causal structure the idea that cause and effect can no longer be sharply distinguished.  Motivated both by experimentation with quantum switches and quantum gravity there can be situations in which there is no matter-of-the-fact as to what the causal structure of spacetime is.  This meeting will bring together workers in Quantum Foundations and Quantum Gravity in both theoretical experimental physics to discuss the state of the art of current research and set new directions for this emerging subdiscipline.

Our conference covers three related subjects: quantum fault-tolerance magic states and resource theories and quantum computational phases of matter. The linking elements between them are (a) on the phenomenological side the persistence of computational power under perturbations and (b) on the theory side symmetry. The latter is necessary for the working of all three. The subjects are close but not identical and we expect cross-fertilization between them.Fault tolerance is an essential component of universal scalable quantum computing.However known practical methods of achieving fault tolerance are extremely resource intensive. Distillation of magic states is in the current paradigm of fault-tolerance the costliest operational component by a large margin. It is therefore pertinent to improve the efficiency of such procedures study theoretical limits of efficiency and more generally to establish a resource theory of quantum state magic. During the workshop we will focus on a fundamental connection between fault-tolerant protocols and symmetries.``Computational phases of matters are a surprising link between quantum computation and condensed matter physics. Namely in the presence of suitable symmetries the ground states of spin Hamiltonians have computational power within the scheme of measurement-based quantum computation and this power is uniform across physical phases. Several computationally universal phases have to date been discovered. This subject is distinct from the above but linked to them by the feature of persistence of computational power under deformations and deviations.

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

The foundations of quantum mechanics have been revitalized in the past few decades by three developments:  (i) the influence of quantum computation and quantum information theory (ii) studies of the interplay between quantum theory and relativity particularly the analysis of indefinite causal structure and (iii) proposals to reconstruct quantum theory from basic axioms.  There have also been very interesting developments in understanding and classifying no=locality and contextuality using tools from sheaf theory and cohomology as well as operator algebras and category theory. The International Congress of Mathematical Physics is a natural forum for the discussion of these topics.  In the past there have been satellite workshops on topics like Operator algebras and quantum statistical mechanics which also address fundamental issues.  The modern study of quantum foundations is very much influenced and informed by mathematics:  sheaf theory and cohomology category theory information theory convex analysis in addition to the continuing interest in operator algebras and functional analysis. The aim of the workshop is to bring together researchers who have made substantial contribution to the recent developments.  The workshop will be held at Perimeter Institute over a five day period from July 30

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.

2017 marks 50 years since the seminal 1967 article of Kochen and Specker proving that quantum theory fails to admit of a noncontextual model.  Despite the fact that the Kochen-Specker theorem is one of the seminal results concerning the foundations of quantum theory, there has never been a large conference dedicated to the subject.  The 50-year anniversary of the theorem seems an opportune time to remedy this oversight.  Furthermore, in the last decade, there have been tremendous advances in the field.  New life has been breathed into the subject as old conceptual issues have been re-examined from a new information-theoretic perspective. Importantly, there has been great progress in making the notion of noncontextuality robust to noise and therefore experimentally testable.  Finally, there is mounting evidence that the resource that powers many quantum advantages for information processing is contextuality.  In particular, it has been shown to underlie the possibility of universal quantum computation.  Many groups worldwide are actively engaged in advancing our knowledge on each of these fronts and in deepening our understanding of the distinction between quantum and classical theories through the lens of contextuality.  Through this conference, we aim to bring together leading researchers in the field in order to develop a broader perspective on the issues, draw connections between different approaches, foster a more cohesive community, and set objectives for future research.