Quantum Filtering in Coherent States

TL;DR

This paper derives a quantum filtering equation for systems observed through non-demolition measurements with input fields in arbitrary coherent states, extending the theoretical framework of quantum filtering.

Contribution

It introduces a generalized quantum filtering equation for non-demolition measurements with coherent state inputs, broadening the applicability of quantum filtering theory.

Findings

Derived the Belavkin-Kushner-Stratonovich equation for coherent states

Extended quantum filtering framework to non-vacuum input fields

Provided mathematical formulation for quantum systems with coherent state inputs

Abstract

We derive the form of the Belavkin-Kushner-Stratonovich equation describing the filtering of a continuous observed quantum system via non-demolition measurements when the statistics of the input field used for the indirect measurement are in a general coherent state.