Indirect Measurement Process Parameterized by Nonunitary System - Pointer Interaction

TL;DR

This paper develops a formalism for indirect quantum state measurement involving nonunitary pointer-system interactions, applying it to cavity photodetection to analyze information characteristics.

Contribution

It introduces a differential equation framework for superoperators in nonunitary measurement processes, advancing understanding of quantum measurement dynamics.

Findings

Superoperator equations describe nonunitary measurement evolution.

Application to cavity photodetection reveals measurement information properties.

Formalism enhances modeling of realistic quantum measurement scenarios.

Abstract

An indirect quantum state measurement process is under investigation. Common evolution of detector's microscopic part (pointer) and measured system (target) is considered to be nonunitary due to the interaction between pointer and environment. System of differential equations for superoperators, which map initial target state to it's conditional final state is obtained. Developed formalism is applied to the problem of cavity quantum mode photodetection to investigate basic information characteristics of this measurement process.