Physical Realizability of An Open Spin System

Abstract

Coherent feedback control considers purely quantum controllers in order to overcome disadvantages such as the acquisition of suitable quantum information, quantum error correction, etc. These approaches lack a systematic characterization of quantum realizability. Recently, a condition characterizing when a system described as a linear stochastic differential equation is quantum was developed. Such condition was named physical realizability, and it was developed for linear quantum systems satisfying the quantum harmonic oscillator canonical commutation relations. In this context, open spin systems escape the realm of the current known condition. The goal of this paper is to provide a characterization for physical realizability of a single particle open spin system. Show more