Enhanced Two-Parameter Phase-Space-Displacement Estimation Close To A Dissipative Phase Transition

I propose a quantum sensor based on a driven-dissipative quantum system for the joint estimation of two conjugated variables characterizing the phase-space displacement. The quantum probe consists of a lattice system with two-level atoms and bosonic modes which interact via dipolar coupling. Interplay between the coherent dynamics and dissipative processes of losses of bosonic excitations leads to a steady state which exhibits a nonanalytical behavior. I show that close to the dissipative phase transition, the sensitivity of one of the conjugated parameters, i.e., either the magnitude or the phase of the displacement, can be significantly enhanced. Moreover, I show that the sum of the measurement uncertainties of the two parameters can overcome the standard quantum limit.