Coherent dynamical control of quantum processes

TL;DR

This paper develops a Markovian master equation for quantum process control, enabling optimal local coherent manipulation of open quantum systems to achieve desired target processes at specific times.

Contribution

It introduces a novel process-based master equation and extends control techniques for precise manipulation of quantum processes in open systems.

Findings

Effective suppression of decoherence demonstrated

Successful simulation of quantum gates achieved

Passive environment control shown to be feasible

Abstract

Manipulation of a quantum system requires the knowledge of how it evolves. To impose that the dynamics of a system becomes a particular target operation (for any preparation of the system), it may be more useful to have an equation of motion for the dynamics itself--rather than the state. Here we develop a Markovian master equation for the process matrix of an open system, which resembles the Lindblad Markovian master equation. We employ this equation to introduce a scheme for optimal local coherent process control at target times, and extend the Krotov technique to obtain optimal control. We illustrate utility of this framework through several quantum coherent control scenarios, such as optimal decoherence suppression, gate simulation, and passive control of the environment, in all of which we aim to simulate a given terminal process at a given final time.