The Phase Sensitivities for Different Phase-Shift Configurations in an SU(1,1) Interferometer  

作　　者：Fan Wang Wei Zhong Lan Zhou Yu-Bo Sheng 王凡;钟伟;周澜;盛宇波(Institute of Quantum Information and Technology,Nanjing University of Posts and Telecommunications,Nanjing 210003,China;National Laboratory of Solid State Microstructures,Nanjing University,Nanjing 210093,China;School of Science,Nanjing University of Posts and Telecommunications,Nanjing 210003,China;Key Lab of Broadband Wireless Communication and Sensor Network Technology,Nanjing University of Posts and Telecommunications,Ministry of Education,Nanjing 210003,China)

机构地区：[1]Institute of Quantum Information and Technology,Nanjing University of Posts and Telecommunications,Nanjing 210003,China [2]National Laboratory of Solid State Microstructures,Nanjing University,Nanjing 210093,China [3]School of Science,Nanjing University of Posts and Telecommunications,Nanjing 210003,China [4]Key Lab of Broadband Wireless Communication and Sensor Network Technology,Nanjing University of Posts and Telecommunications,Ministry of Education,Nanjing 210003,China

出　　处：《Communications in Theoretical Physics》2019年第12期1435-1442,共8页理论物理通讯（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grant Nos.11747161 and 11974189;the China Postdoctoral Science Foundation under Grant No.2018M642293

摘　　要：We theoretically study the phase sensitivities of two different phase-shift configurations in an SU(1,1)interferometer with coherent■squeezed vacuum states.According to quantum Cramér-Rao theorem,we analytically obtain the ultimate phase sensitivities for two types of phase shift accumulating in one-and two-arm.Compared with the case of one-arm phase shift,the model with phase shift encoding in both arms may provide a better sensitivity when the strength of squeezed vacuum state is large enough.Furthermore,we discuss the achievable sensitivities with the homodyne measurement by invoking of error-propagation formula.In addition,we study the effect of internal and outernal photon losses on the phase sensitivity of the SU(1,1)interferometer and find that the unbalanced interferometer is helpful to improve precision even with high external losses.

关 键 词：SU(1 1)interferometer quantum Fisher information one-and two-arm phase shifts Homodyne measurement 

分 类 号：O43[机械工程—光学工程]