Quantum Filtering (Quantum Trajectories) for Systems Driven by Fields in Single Photon States and Superposition of Coherent States

TL;DR

This paper develops quantum filtering equations for systems driven by non-classical fields, including superpositions of single photons and coherent states, enabling better modeling of quantum systems under realistic quantum light inputs.

Contribution

It derives stochastic master equations for quantum systems driven by superpositions of single photon and coherent states, extending quantum filtering theory to more complex non-classical inputs.

Findings

Derived quantum filters for superpositions of single photon and vacuum states.

Extended quantum filtering to multiple coherent states.

Provided mathematical framework for non-classical field-driven systems.

Abstract

We derive the stochastic master equations, that is to say, quantum filters, and master equations for an arbitrary quantum system probed by a continuous-mode bosonic input field in two types of non-classical states. Specifically, we consider the cases where the state of the input field is a superposition or combination of: (1) a continuous-mode single photon wave packet and vacuum, and (2) any number of continuous-mode coherent states.