Phase estimation of phase shifts in two arms for an SU(1,1) interferometer with coherent and squeezed vacuum states

Gong Qian-Kun¹, Li Dong¹, Yuan Chun-Hua^{1, 4, †}, Qu Ze-Yu^{1, 3}, Zhang Wei-Ping^{2, 4}

(color online) The QCRB versus the η for (a) two coherent states input and (b) coherent ⊗ squeezed state input. The inset in panel (b) shows a zoom of the graph for small values of η. Here, N_in = 200 and g = 1.5.