Feedback Control of Linear Dynamical Quantum Systems

Abstract

This chapter introduces and treats the topic of quantum feedback control on linear quantum systems. Two distinct approaches to feedback control of quantum systems are considered: measurement-based feedback control and coherent feedback control. For measurement-based feedback control, the notions of controlled Hudson–Parthasarathy QSDEs and controlled quantum filtering equations are introduced. Three control problems are formulated and solved: measurement-based linear quadratic Gaussian control, coherent linear quadratic Gaussian control, and coherent feedback H∞ control. Examples are provided to illustrate each control method.