Phase estimation for an SU(1,1) interferometer in the presence of phase diffusion and photon losses

TL;DR

This paper analyzes the quantum Fisher information of an SU(1,1) interferometer under realistic noise conditions, deriving bounds on phase estimation precision considering phase diffusion and photon losses.

Contribution

It introduces a generalized phase transform incorporating phase diffusion and derives analytical QFI bounds under combined noise effects.

Findings

Derived analytical QFI considering phase diffusion and photon losses.

Established upper bounds on decoherence coefficients for surpassing the standard quantum limit.

Provided insights into quantum precision limits in noisy interferometric setups.

Abstract

We theoretically study the quantum Fisher information (QFI) of the SU(1,1) interferometer with phase shifts in two arms taking account of realistic noise effects. A generalized phase transform including the phase diffusion effect is presented by the purification process. Based on this transform, the analytical QFI and the bound to the quantum precision are derived when considering the effects of phase diffusion and photon losses simultaneously. To beat the standard quantum limit with the reduced precision of phase estimation due to noisy, the upper bounds of decoherence coefficients as a function of total mean photon number are given.