논문 해외 국제전문학술지(SCI급) Faithful measure of quantum non-Gaussianity via quantum relative entropy
- 학술지 구분 국제전문학술지(SCI급)
- 게재년월 2019-07
- 저자명 Jiyong Park, Jaehak Lee, Kyunghyun Baek, Se-Wan Ji, and Hyunchul Nha
- 학술지명 Physical Review A
- 발행처명 American Physical Society
- 발행국가 해외
- 논문언어 외국어
- 전체저자수 5
홈페이지논문 초록 (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.