Feedback Control Using Only Quantum Back-Action

TL;DR

This paper demonstrates that quantum systems can be effectively controlled solely through the quantum back-action of continuous weak measurements, eliminating the need for Hamiltonian feedback.

Contribution

It introduces a novel feedback control method that relies exclusively on quantum back-action, challenging traditional Hamiltonian-based control strategies.

Findings

Quantum back-action can be used for effective control of quantum systems.

Control performance comparable to traditional Hamiltonian feedback.

Adaptive measurement-based control is feasible and effective.

Abstract

The traditional approach to feedback control is to apply forces to a system by modifying the Hamiltonian. Here we show that quantum systems can be controlled without any Hamiltonian feedback, purely by exploiting the random quantum back-action of a continuous weak measurement. We demonstrate that, quite remarkably, the quantum back-action of such an adaptive measurement is just as effective at controlling quantum systems as traditional feedback.