Heisenberg-scaling sensitivity in the estimation of two parameters in a Mach-Zehnder interferometer

TL;DR

This paper proposes a practical quantum metrology scheme that uses squeezed and coherent light in a Mach-Zehnder interferometer to achieve Heisenberg-limited sensitivity in estimating two phase parameters simultaneously.

Contribution

It introduces an experimentally feasible method for simultaneous two-parameter estimation at the Heisenberg limit using specific quantum states and detection techniques.

Findings

Achieves Heisenberg-limited sensitivity in two-parameter estimation

Utilizes a combination of squeezed and coherent states

Employs homodyne detection for optimal measurement

Abstract

Achieving the ultimate quantum precision in the estimation of multiple physical parameters simultaneously is a challenge in quantum metrology due to fundamental limitations and experimental challenges in harnessing the necessary quantum resources. We propose an experimentally feasible scheme to reach Heisenberg limited sensitivity in the simultaneous estimation of two unknown phase parameters in a Mach-Zehnder interferometer by using a squeezed and a coherent state of light as input and homodyne detections at the outputs.