光子增加双模压缩真空态在马赫-曾德尔干涉仪相位测量中的应用  

Application of photon-added two-mode squeezed vacuum states to phase estimation based on Mach-Zehnder interferometer

作　　者：王帅 眭永兴 孟祥国[2] Wang Shuai;Sui Yong-Xing;Meng Xiang-Guo(School of Mathematics and Physics,Jiangsu University of Technology,Changzhou 213001,China;School of Physics Science and Information Technology,Liaocheng University,Liaocheng 252059,China)

机构地区：[1]江苏理工学院数理学院,常州213001 [2]聊城大学物理科学与信息工程学院,聊城252059

出　　处：《物理学报》2020年第12期43-53,共11页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11404040);江苏省高校“青蓝工程”资助的课题。

摘　　要：量子度量学主要是利用量子效应来提高参数估计的精度,以期突破标准量子极限,甚至达到海森伯极限.本文研究了一般光子增加双模压缩真空态作为马赫-曾德尔干涉仪的探测态时,在何种情况下能够提高待测相位的测量精度.根据量子Fisher信息理论,尽管在探测态具有相同的平均光子数这一约束条件下,对称的和非对称的光子增加操作并不能提高相位的测量精度.但若是在给定初始压缩参数的情况下,对称的和非对称的光子增加操作却能够增强相位的测量精度.另外,基于宇称测量的研究结果表明,对于对称光子增加双模压缩真空态,只有当待测相位趋于零时,宇称测量才是最优测量.而对于非对称光子增加双模压缩真空态,宇称测量并不是最优测量方案.Quantum metrology is to estimate accurately the value of an unknown parameter with the assistance of the quantum effects,in order to break through the standard quantum limit,even reach the Heisenberg limit.In this work,we study the performance of a general photon-added two-mode squeezed vacuum state that is taken as a detection state of a Mach-Zehnder interferometer.Based on quantum Fisher information,within the constraint on the total mean photon number,symmetric and asymmetric photon addition cannot improve the ultimate phase sensitivity.However,for a given initial squeezing parameter,on this occasion,the symmetric and asymmetric photon addition can improve the ultimate phase sensitivity.Compared with the asymmetric photon-added two-mode squeezed vacuum state,the symmetric one can well improve the ultimate phase sensitivity.This may be because it is always better to implement the symmetric photon addition rather than the asymmetric one in order to increase the mean photon number of the resulting state.On the other hand,via parity detection,the symmetric and asymmetric photon-added two-mode squeezed vacuum state can indeed improve the phase sensitivity of a Mach-Zehnder interferometer for a given initial squeezing parameter.Based on the parity detection,within a constraint on the mean photon number,although the two-mode squeezed vacuum state can give the better phase sensitivity at the optimal phase shift(j=0),the phase sensitivity offered by the symmetric and asymmetric photon-added two-mode squeezed vacuum states are both more stable around j=0 than by the two-mode squeezed vacuum state.In addition,we show that for the symmetric photon-added two-mode squeezed vacuum state,parity detection is an optimal detection only when the optimal phase shift approaches to zero.When the phase shift slightly deviates from zero,the parity detection is not an optimal detection scheme.Finally,for all values of the phase shift,our results also clearly show that the parity detection is not an optimal detection scheme for the asym

关 键 词：量子度量学 非高斯纠缠态 马赫-曾德尔干涉仪 

分 类 号：O431.2[机械工程—光学工程]