Enhancement of Sensitivity by Initial Phase Matching in SU(1,1) Interferometers  

作　　者：Xiao Xiao Hong-Bin Liang Guo-Long Li Xiao-Guang Wang 肖骁;梁宏宾;李国龙;王晓光

机构地区：[1]Zhejiang Institute of Modern Physics, Department of Physics, Zhejiang University

出　　处：《Communications in Theoretical Physics》2019年第1期37-42,共6页理论物理通讯（英文版）

基　　金：Supported by the National Key Research and Development Program of China under Grant Nos.2017YFA0304202 and 2017YFA0205700;the NSFC through Grant No.11875231;the Fundamental Research Funds for the Central Universities through Grant No.2018FZA3005

摘　　要：We derive a general phase-matching condition(PMC) for enhancement of sensitivity in SU(1,1) interferometers. Under this condition, the quantum Fisher information(QFI) of two-mode SU(1,1) interferometry becomes maximal with respect to the relative phase of two modes, for the case of an arbitrary state in one input port and an even(odd) state in the other port, and the phase sensitivity is enhanced. We also find that optimal parameters can let the QFI in some areas achieve the Heisenberg limit for both pure and mixed initial states. As examples, we consider several input states: coherent and even coherent states, squeezed vacuum and even coherent states, squeezed thermal and even coherent states. Furthermore, in the realistic scenario of the photon loss channel, we investigate the effect of photon losses on QFI with numerical studies. We find the PMC remains unchanged and is not affected by the transmission coefficients for the above input states. Our results suggest that the PMC can exist in various kinds of interferometers and the phase-matching is robust to even strong photon losses.

关 键 词：quantum FISHER information SU(1 1) PARAMETER estimation PHASE-MATCHING condition 

分 类 号：O4[理学—物理]