Phase estimation of definite photon number states by using quantum circuits

TL;DR

This paper introduces a quantum circuit-based method for phase estimation in optical interferometry, analyzing the performance of different photon-number states under photon loss using Bayesian inference and Fisher information.

Contribution

It presents a novel approach to map optical interferometry into quantum circuits for phase estimation, including simulation of photon loss and comparison of photon-number states.

Findings

Different photon-number states show varying estimation precisions.

Fisher information analysis identifies optimal measurement schemes.

Quantum circuit simulation effectively models photon loss effects.

Abstract

We propose a method to map the conventional optical interferometry setup into quantum circuits. The unknown phase shift inside a Mach-Zehnder interferometer in the presence of photon loss is estimated by simulating the quantum circuits. For this aim, we use the Bayesian approach in which the likelihood functions are needed, and they are obtained by simulating the appropriate quantum circuits. The precision of four different definite photon-number states of light, which all possess six photons, is compared. In addition, the fisher information for the four definite photon-number states in the setup is also estimated to check the optimality of the chosen measurement scheme.