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

2 Citations (Scopus)

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

    Fingerprint

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Cite this