Optimal conventional measurements for quantum-enhanced interferometry

This is the authors' abstract. We don't add key points for this paper.

A major obstacle to attaining the fundamental precision limit of phase estimation in interferometry is the identification and implementation of the optimal measurement. Here we demonstrate that this can be accomplished by the use of three conventional measurements among interferometers with Bayesian estimation techniques. Conditions that hold for the precision limit to be attained with these measurements are obtained by explicitly calculating the Fisher information. Fortunately, these conditions are naturally satisfied in most interferometric experiments. We apply our results to an atomic spectroscopy experiment and examine the robustness of phase sensitivity for the two-axis counter-twisted state suffering from detection noise.