Faithful measure of quantum non-Gaussianity via quantum relative entropy

Jiyong Park, Jaehak Lee, Kyunghyun Baek, Se Wan Ji, Hyunchul Nha

Research output: Contribution to journalArticle

Abstract

We introduce a measure of quantum non-Gaussianity (QNG) for those quantum states not accessible by a mixture of Gaussian states in terms of quantum relative entropy. Specifically, we employ a convex-roof extension using all possible mixed-state decompositions beyond the usual pure-state decompositions. We prove that this approach brings a QNG measure fulfilling the properties desired as a proper monotone under Gaussian channels and conditional Gaussian operations. As an illustration, we explicitly calculate QNG for the noisy single-photon states and demonstrate that QNG coincides with non-Gaussianity of the state itself when the single-photon fraction is sufficiently large.

Original languageEnglish
Article number012333
JournalPhysical Review A
Volume100
Issue number1
DOIs
Publication statusPublished - 23 Jul 2019

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entropy
decomposition
roofs
photons

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

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Faithful measure of quantum non-Gaussianity via quantum relative entropy. / Park, Jiyong; Lee, Jaehak; Baek, Kyunghyun; Ji, Se Wan; Nha, Hyunchul.

In: Physical Review A, Vol. 100, No. 1, 012333, 23.07.2019.

Research output: Contribution to journalArticle

Park, Jiyong ; Lee, Jaehak ; Baek, Kyunghyun ; Ji, Se Wan ; Nha, Hyunchul. / Faithful measure of quantum non-Gaussianity via quantum relative entropy. In: Physical Review A. 2019 ; Vol. 100, No. 1.
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