Controlling open quantum systems using fast transitions

TL;DR

This paper introduces a time-optimal control protocol for open quantum systems that leverages diabatic transitions to achieve rapid, high-accuracy control while respecting quantum speed limits, effectively mitigating decoherence.

Contribution

The authors develop a novel control scheme based on diabatic and sudden switch transitions that is optimal in speed and suitable for open quantum systems, addressing decoherence challenges.

Findings

Achieves control speeds at quantum speed limit bounds

Maintains high accuracy in open quantum systems

Effectively mitigates decoherence during control processes

Abstract

Unitary control and decoherence appear to be irreconcilable in quantum mechanics. When a quantum system interacts with an environment, control strategies usually fail due to decoherence. In this letter, we propose a time-optimal unitary control protocol suitable for quantum open systems. The method is based on succesive diabatic and sudden switch transitions in the avoided crossings of the energy spectra of closed systems. We show that the speed of this control protocol meets the fundamental bounds imposed by the quantum speed limit, thus making this scheme ideal for application where decoherence needs to be avoided. We show that our method can achieve complex control strategies with high accuracy in quantum open systems.