A1 Refereed original research article in a scientific journal
Set Coherence: Basis-Independent Quantification of Quantum Coherence
Authors: Designolle Sébastien, Uola Roope, Luoma Kimmo, Brunner Nicolas
Publisher: AMER PHYSICAL SOC
Publication year: 2021
Journal: Physical Review Letters
Journal name in source: PHYSICAL REVIEW LETTERS
Journal acronym: PHYS REV LETT
Article number: ARTN 220404
Volume: 126
Issue: 22
Number of pages: 6
ISSN: 0031-9007
DOI: https://doi.org/10.1103/PhysRevLett.126.220404
Abstract
The coherence of an individual quantum state can be meaningfully discussed only when referring to a preferred basis. This arbitrariness can, however, be lifted when considering sets of quantum states. Here we introduce the concept of set coherence for characterizing the coherence of a set of quantum systems in a basis-independent way. We construct measures for quantifying set coherence of sets of quantum states as well as quantum measurements. These measures feature an operational meaning in terms of discrimination games and capture precisely the advantage offered by a given set over incoherent ones. Along the way, we also connect the notion of set coherence to various resource-theoretic approaches recently developed for quantum systems.
The coherence of an individual quantum state can be meaningfully discussed only when referring to a preferred basis. This arbitrariness can, however, be lifted when considering sets of quantum states. Here we introduce the concept of set coherence for characterizing the coherence of a set of quantum systems in a basis-independent way. We construct measures for quantifying set coherence of sets of quantum states as well as quantum measurements. These measures feature an operational meaning in terms of discrimination games and capture precisely the advantage offered by a given set over incoherent ones. Along the way, we also connect the notion of set coherence to various resource-theoretic approaches recently developed for quantum systems.