Quantum feedback: theory, experiments, and applications

TL;DR

This paper reviews the development of quantum feedback control, covering theoretical foundations, experimental demonstrations, and practical applications, highlighting recent progress and future prospects in controlling quantum systems.

Contribution

It provides a comprehensive overview of quantum feedback methods, integrating theory, experiments, and applications, and discusses recent advancements and future directions.

Findings

Rapid experimental progress in quantum measurement and control

Implementation of feedback control in various quantum systems

Anticipation of further advances in feedback protocol precision

Abstract

The control of individual quantum systems is now a reality in a variety of physical settings. Feedback control is an important class of control methods because of its ability to reduce the effects of noise. In this review we give an introductory overview of the various ways in which feedback may be implemented in quantum systems, the theoretical methods that are currently used to treat it, the experiments in which it has been demonstrated to-date, and its applications. In the last few years there has been rapid experimental progress in the ability to realize quantum measurement and control of mesoscopic systems. We expect that the next few years will see further rapid advances in the precision and sophistication of feedback control protocols realized in the laboratory.