Gauge Theories, Constrained Hamiltonian and Digital Quantum Computers

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

Speaker: M.Hopjan (J. Stefan Institute, Ljubljana) Abstract Recently it was shown, in the three-dimensional Anderson model [1] and the avalanche model of ergodicity breaking transitions [2], that the spectral form factor and the Thouless time extracted from the spectral form factor are scale invariant quantities at eigenstate transition. Thus they represent useful measures for characterisation […]

Speaker: Andrew Nemec (Duke University) Abstract Hybrid codes simultaneously encode both quantum and classical information together, giving an advantage over coding schemes where the quantum and classical information are transmitted separately. We construct the first known families of hybrid codes that are guaranteed to provide an advantage over quantum codes, as well as also giving […]

Speaker: Carlos L. Benavides-Riveros (MPI for the Physics of Complex Systems, Dresden / University of Trento) Abstract Determining the properties of the excitations in quantum many-body systems is a fundamental problem across almost all sciences. For instance, quantum excited states underpin new states of matter, support biological processes such as vision, or determine optoelectronic properties […]