Paradigms for Quantum Feedback Control

TL;DR

This review paper comprehensively surveys quantum feedback control, covering foundational theories, models, objectives, and connections to quantum chaos, highlighting recent developments and key concepts in the field.

Contribution

It provides a unified overview of quantum feedback control theories, models, and objectives, clarifying essential ideas and recent advances for researchers.

Findings

Quantum feedback enables rapid state preparation and entanglement generation.

Comparison between coherent feedback and open-loop control models.

Exploration of the link between quantum feedback and quantum chaos.

Abstract

In this review paper, we survey the main concepts and some of the recent developments in quantum feedback control. For consistency and clarity, essential ideas and notations in the theory of open quantum systems and quantum stochastic calculus, as well as continuous measurement theory are developed. We give a general description of quantum feedback control, set up a coherent model and compare it to open-loop designs. Objectives which can be achieved by feedback, such as rapid state preparation and purification or entanglement generation are formulated and analyzed, based on the relevant literature. The connection between quantum feedback and quantum chaos is also described and unravelled which, apart from its theoretical curiosity, can shed more light on some of the intrinsic properties of this control paradigm.