Quantum metrology with entangled coherent states

TL;DR

This paper introduces an enhanced quantum phase estimation method using entangled coherent states, outperforming other states in precision under ideal and lossy conditions, and is feasible with current optical technology.

Contribution

It demonstrates that entangled coherent states provide superior phase estimation accuracy compared to NOON, BAT, and optimal states, even with modest particle numbers.

Findings

Entangled coherent states achieve the smallest phase variance.

The method outperforms NOON, BAT, and optimal states.

Implementation is feasible with current optical technology.

Abstract

We present an improved phase estimation scheme employing entangled coherent states and demon- strate that the states give the smallest variance in the phase parameter in comparison to NOON, BAT and "optimal" states under perfect and lossy conditions. As these advantages emerge for very modest particle numbers, the optical version of entangled coherent state metrology is achievable with current technology.