Enhanced quantum phase estimation with $q$-deformed nonideal nonclassical light

TL;DR

This paper explores how q-deformed nonclassical light states can enhance phase estimation precision in quantum interferometry, demonstrating improved sensitivity and the effectiveness of photon counting as a measurement strategy.

Contribution

It introduces a method to analyze q-deformed photon states in quantum phase estimation, deriving likelihoods and Fisher information, showing improved performance with increasing q-deformation.

Findings

Photon counting remains optimal even for deformed states.

Classical and quantum Fisher information are in exact agreement.

Phase sensitivity improves with increasing q-deformation.

Abstract

We investigate quantum phase estimation in a Mach-Zehnder interferometer using q-deformed photon states, including q-coherent and q-cat states, which model realistic deviations from ideal light sources. By deriving closed-form photon count likelihoods via the Jordan-Schwinger mapping, we compute the quantum and classical Fisher information and perform Bayesian inference on simulated detector data. Our results show that photon counting remains an optimal measurement strategy even for deformed states, with classical and quantum Fisher information in exact agreement. Furthermore, the phase sensitivity improves with increasing q-deformation, indicating enhanced metrological performance driven by nonclassical photon statistics. These findings highlight the utility of q-deformed states in quantum sensing.