Probing Nonclassicality of Two-Mode SU (2) Generator Based on Quantum Fisher Information  

作　　者：Dan Zhang Qiang Zheng Xiao-Guang Wang 张丹;郑强;王晓光

机构地区：[1]School of Chemistry and Material Science, Guizhou Normal University [2]School of Mathematics, Guizhou Normal University [3]Quantum Physics and Quantum Information Division, Beijing Computational Science Research Center [4]Zhejiang Institute of Modern Physics, Department of Physics, Zhejiang University

出　　处：《Communications in Theoretical Physics》2018年第11期552-558,共7页理论物理通讯（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grant No.11365006;the Natural Science Foundation of Guizhou Province under Grant No.QKHLHZ[2015]7767

摘　　要：Nonclassicality is an essential but still open question in quantum mechanics. Here, utilizing the maximum value of quantum Fisher information, we suggest a new version of the nonclassical criterion for SU(2) generator realized by two bosonic modes. As an application of the criterion, the system of two coupled nonlinear nanomechanical resonators is considered. And the nonclassicality of the phonon state in the dynamical evolution is explored. The system has a dynamical phase transition from the tunnelling phase to the self-trapping phase by tuning the coupling strength. It is found that for the tunnelling phase, the phonon state is nonclassical in the full time evolution. And for the self-trapping phase, the evolved phonon state is still nonclassical in the full time with a relatively large coupling strength, while it is nonclassical i n the most of time (but not all) with a small coupling strength. Quantum coherence has distinct different behaviors in the two phases.

关 键 词：quantum FISHER information NONCLASSICALITY COHERENCE 

分 类 号：O4[理学—物理]