A de Finetti theorem for quantum causal structures

Speaker: Fabio Costa (University of Queensland) Abstract What does it mean for a causal structure to be “unknown”? Can we even talk about “repetitions” of an experiment without prior knowledge of causal relations? And under what conditions can we say that a set of processes are independent and identically distributed (i.i.d.)? Similar questions for classical […]

Speaker: Robert Spekkens (Perimeter Institute for Theoretical Physics) Abstract Can the effectiveness of a medical treatment be determined without the expense of a randomized controlled trial? Can the impact of a new policy be disentangled from other factors that happen to vary at the same time? Questions such as these are the purview of the field […]

Speaker: Adamantia Zampeli (Universidad Nacional Autónoma de México) Abstract In this talk, I will introduce the main elements and ideas of the general boundary formulation [R. Oeckl. A local and operational framework for the foundations of physics. Advances in Theoretical and Mathematical Physics, 23(2):437–592, 2019. arXiv: 1610.09052.]. This is a formalism inspired by quantum gravity approaches […]

Speaker: Dorota Maria Grabowska Abstract Constrained Hamiltonians are ubiquitous in fundamental physics, as any gauge theory – general relativity, electromagnetism, Yang–Mills, string theory – all result in such Hamiltonians. Unfortunately, implementing these Hamiltonians on digital quantum computers poses a number of difficulties, both theoretical and practical. In this talk, I will discuss our recent work on […]

Speaker: Dominik Šafránek (Institute for Basic Science, South Korea) Abstract I will introduce a protocol which allows to unitarily extract work out of sources of quantum states characterized only by a single type of coarse measurement. This defines a new notion of extractable work, which we call observational ergotropy, because it is directly related to observational […]

Speaker: Pedro Dieguez (ICTQT) Abstract Wheeler’s delayed-choice experiment, a scenario wherein a classical apparatus, typically an interferometer, is settled only after the quantum system has entered it, has corroborated the complementarity principle. However, the quantum version of Wheeler's delayed-choice experiment has challenged the robustness of this principle. Based on the visibility at the output of […]

Speaker: Eric Aurell (KTH Royal Institute of Technology) Abstract

Speaker: Giovanni Scala (ICTQT, UG) Abstract We introduce a family of positive linear maps in the algebra of 3 x3 complex matrices, which generalizes the seminal positive non-decomposable map originally proposed by Choi. Necessary and sufficient conditions for decomposability are derived and demonstrated. The proposed maps offer a new method for the analysis of bound entangled […]

Speaker: Satoshi Yoshida (University of Tokyo) Abstract In this work, we report a deterministic and exact algorithm to reverse any unknown qubit-encoding isometry operation. We present the semidefinite programming (SDP) to search the Choi matrix representing a quantum circuit reversing any unitary operation. We derive a quantum circuit transforming four calls of any qubit-unitary operation into […]

Speaker: Adam Sawicki (Centre for Theoretical Physics, Polish Academy of Sciences, Warsaw) Abstract