Alternative non-Gaussianity measures for quantum states based on quantum fidelity  

作　　者：Cheng Xiang Shan-Shan Li Sha-Sha Wen Shao-Hua Xiang 向成;李珊珊;文莎莎;向少华(College of Electrical and Information Engineering,Huaihua University,Huaihua 418008 China;Hunan Provincial Key Laboratory of Ecological Agriculture Intelligent Control Technology,Huaihua 418008,China)

机构地区：[1]College of Electrical and Information Engineering,Huaihua University,Huaihua 418008 China [2]Hunan Provincial Key Laboratory of Ecological Agriculture Intelligent Control Technology,Huaihua 418008,China

出　　处：《Chinese Physics B》2022年第3期192-200,共9页中国物理B（英文版）

基　　金：Project supported by the Natural Science Foundation of Hunan Province, China (Grant No. 2021JJ30535);the Science and Technology Innovation Foundation for College Students in Hunan Province of China (Grant No. 2020RC1013);the Research Foundation for Young Teachers from the Education Department of Hunan Province of China (Grant No. 20B460)。

摘　　要：We propose three alternative measures for non-Gaussianity of quantum states: sine distance, Bures angle, and Bures distance, which are based on quantum fidelity introduced by Wang [Phys. Lett. A 373 58(2008)]. Using them, we evaluate the non-Gaussianity of some relevant single-mode and two-mode non-Gaussian states and find a good consistency of the three examined measures. In addition, we show that such metrics can exactly quantify the degree of Gaussianity of even Schrödinger-cat-like states of small amplitudes that can not be measured by other known non-Gaussianity measures such as the Hilbert–Schmidt metric and the relative entropy metric. We make a comparative study between all existing nonGaussianity measures according to the metric axioms and point out that the sine distance is the best candidate among them.

关 键 词：NON-GAUSSIANITY quantum fidelity non-Gaussian states sine metric 

分 类 号：O413[理学—理论物理]