Weak measurements and the joint estimation of phase and phase diffusion

Abstract

Weak measurements offer the possibility of tuning the information acquired on a system, hence the imposed disturbance. This suggests that it could be a useful tool for multiparameter estimation, when two parameters cannot be measured simultaneously at the quantum limit. Here we discuss their use for phase estimation in the presence of phase diffusion in the context of polarimetry, a scenario that is conveniently cast in terms of a two-level quantum system in many relevant cases.