Quantum Enhanced Multiple Phase Estimation

Understand

We study the simultaneous estimation of multiple phases as a discretised model for the imaging of a phase object.

• We identify quantum probe states that provide an enhancement compared to the best quantum scheme for the estimation of each individual phase separately, as well as improvements over classical strategies.
• Our strategy provides an advantage in the variance of the estimation over individual quantum estimation schemes that scales as O(d) where d is the number of phases.
• Finally, we study the attainability of this limit using realistic probes and photon-number-resolving detectors.