Nonideal quantum detectors in Bayesian formalism

TL;DR

This paper develops a Bayesian formalism for continuous solid-state qubit measurement that incorporates various nonideal detector factors, including classical and quantum noises, and applies it to both single and entangled qubits.

Contribution

It introduces a comprehensive Bayesian approach accounting for multiple nonidealities in quantum detectors, extending to entangled qubits.

Findings

Formalism includes classical and quantum noise effects

Applicable to single and entangled qubits

Provides a framework for realistic quantum measurement analysis

Abstract

The Bayesian formalism for a continuous measurement of solid-state qubits is derived for a model which takes into account several factors of the detector nonideality. In particular, we consider additional classical output and backaction noises (with finite correlation), together with quantum-limited output and backaction noises, and take into account possible asymmetry of the detector coupling. The formalism is first derived for a single qubit and then generalized to the measurement of entangled qubits.