Web of Science: 10 citations, Scopus: 8 citations, Google Scholar: citations,
Decoupling with random diagonal unitaries
Nakata, Yoshifumi (Universitat Autònoma de Barcelona. Departament de Física)
Hirche, Christoph (Universitat Autònoma de Barcelona. Departament de Física)
Morgan, Ciara (Universität Leipzig (1991- ). Institut für Theoretische Physik)
Winter, Andreas (Universitat Autònoma de Barcelona. Departament de Física)

Date: 2017
Abstract: We investigate decoupling, one of the most important primitives in quantum Shannon theory, by replacing the uniformly distributed random unitaries commonly used to achieve the protocol, with repeated applications of random unitaries diagonal in the Pauli-Z and -X bases. This strategy was recently shown to achieve an approximate unitary 2-design after a number of repetitions of the process, which implies that the strategy gradually achieves decoupling. Here, we prove that even fewer repetitions of the process achieve decoupling at the same rate as that with the uniform ones, showing that rather imprecise approximations of unitary 2-designs are sufficient for decoupling. We also briefly discuss efficient implementations of them and implications of our decoupling theorem to coherent state merging and relative thermalisation.
Grants: European Commission 600645
European Commission 278106
European Commission 323970
European Commission 267386
Ministerio de Economía y Competitividad FIS2016-80681-P
Ministerio de Economía y Competitividad BES-2014-068888
Ministerio de Economía y Competitividad FIS2013-40627-P
Ministerio de Economía y Competitividad FIS2008-01236
Agència de Gestió d'Ajuts Universitaris i de Recerca 2014/SGR-966
Rights: Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original. Creative Commons
Language: Anglès
Document: Article ; recerca ; Versió publicada
Subject: Quantum information ; Pseudo-randomness ; Unitary design ; Decoupling
Published in: Quantum, Vol. 1 (2017) , p. 18, ISSN 2521-327X

DOI: 10.22331/q-2017-07-21-18


16 p, 581.4 KB

The record appears in these collections:
Articles > Research articles
Articles > Published articles

 Record created 2017-07-19, last modified 2023-05-22



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