Enhancement of parameter estimation by Kerr interaction

TL;DR

This paper investigates how Kerr interaction can enhance quantum parameter estimation, showing that Kerr effects can improve measurement precision especially when Gaussian squeezing is limited or absent.

Contribution

It demonstrates that Kerr interaction can be used to improve quantum parameter estimation when Gaussian squeezing is constrained or unavailable.

Findings

Kerr interaction enhances estimation precision for large amplitude probes.

Gaussian squeezing is optimal when energy is unconstrained.

Kerr effects can surpass current Gaussian squeezing capabilities.

Abstract

We address quantum estimation of displacement and squeezing parameters by the class of probes made of Gaussian states undergoing Kerr interaction. If we fix the overall energy available to the probe, without posing any constraint on the available Gaussian squeezing, then Gaussian squeezing represents the optimal resource for parameter estimation. On the other hand, in the more realistic case where the amount of Gaussian squeezing is fixed, or even absent, then Kerr interaction turns out to be useful to improve estimation, especially for probe states with large amplitude. Our results indicate that precision achievable with current technology Gaussian squeezing may be attained and surpassed for realistic values of the Kerr coupling.