Optimal control of open quantum systems: cooperative effects of driving and dissipation

TL;DR

This paper develops a stochastic optimal control method for open quantum systems that captures cooperative effects of driving and dissipation, enabling phenomena like cooling without internal degrees of freedom.

Contribution

It introduces a generalized Krotov's algorithm for non-Markovian open-system control, revealing effects missed by standard Markovian approaches.

Findings

Control can induce negative entropy change, achieving cooling.

Cooperative effects of driving and dissipation are demonstrated.

Method works without Markovian or rotating-wave approximations.

Abstract

We investigate the optimal control of open quantum systems, in particular, the mutual influence of driving and dissipation. A stochastic approach to open-system control is developed, using a generalized version of Krotov's iterative algorithm, with no need for Markovian or rotating-wave approximations. The application to a harmonic degree of freedom reveals cooperative effects of driving and dissipation that a standard Markovian treatment cannot capture. Remarkably, control can modify the open-system dynamics to the point where the entropy change turns negative, thus achieving cooling of translational motion without any reliance on internal degrees of freedom.