Quantum interferometry via a coherent state mixed with a photon-added squeezed vacuum state

OPTICS COMMUNICATIONS

卷:444

Article

Wang, Shuai^1,2  Xu, Xuexiang³  Xu, Yejun⁴  Zhang, Lijian² 

[1] Jiangsu Univ Technol, Sch Math & Phys, Changzhou 213001, Peoples R China

[2] Nanjing Univ, Coll Engn & Appl Sci, Nanjing 210093, Jiangsu, Peoples R China

[3] Jiangxi Normal Univ, Dept Phys, Nanchang 330022, Jiangxi, Peoples R China

[4] Chizhou Univ, Sch Mech & Elect Engn, Chizhou 247000, Peoples R China

关键词: Parameter estimation;    Mach-Zehnder interferometry;    Quantum metrology;   

DOI  :  10.1016/j.optcom.2019.03.068

来源: Elsevier

【 摘 要 】

We theoretically investigate the phase sensitivity with parity detection on a Mach-Zehnder interferometer with a coherent state combined with a photon-added squeezed vacuum state. Our results show that when the phase shift to be estimated approaches zero, the squeezed vacuum state is indeed the optimal state within a constraint on the average photon number. However, when the phase shift slightly deviates from zero, in terms of parity detection, the photon-added squeezed vacuum state can give the better phase sensitivity than both the squeezed vacuum state and the photon-subtracted squeezed vacuum state when these interferometer states carry many photons. In addition, we also show that the quantum Cramer-Rao bound can be reached by parity detection when the phase shift approaches zero.

【 授权许可】

Free