Stabilization via feedback switching for quantum stochastic dynamics

TL;DR

This paper introduces a feedback switching control method for quantum stochastic dynamics that enhances the speed and robustness of pure-state and subspace preparation, ensuring global asymptotic stability.

Contribution

It presents a novel feedback switching strategy that improves convergence and robustness in quantum state stabilization compared to existing methods.

Findings

Proves global asymptotic stability in mean and almost surely

Demonstrates improved convergence speed and robustness

Outperforms time-based and state-based switching controls

Abstract

We propose a new method for pure-state and subspace preparation in quantum systems, which employs the output of a continuous measurement process and switching dissipative control to improve convergence speed, as well as robustness with respect to the initial conditions. In particular, we prove that the proposed closed-loop strategy makes the desired target globally asymptotically stable both in mean and almost surely, and we show it compares favorably against a time-based and a state-based switching control law, with significant improvements in the case of faulty initialization.