Quantum metrology with two-mode squeezed thermal state: Parity detection and phase sensitivity
Li Heng-Mei1, †, , Xu Xue-Xiang2, Yuan Hong-Chun3, 4, Wang Zhen1
       

Phase sensitivity δϕ as a function of the total photon number N̄ by fixing n̄1 → 2.20112, n̄2 → 5.39877, ϕ → π/2, and modulating r between 3.8 and 4.8 (black solid line), SNL (blue dashed line), and HL (red dot–dashed line).