Reachable Set Characterization of Open Quantum System by Quantum Speed Limit

TL;DR

This paper extends the concept of quantum speed limit (QSL) to characterize the reachable set of open quantum systems, providing a computable and tighter bound that aids in understanding system control capabilities.

Contribution

It generalizes the reachable set characterization using QSL to Markovian open quantum systems, offering explicit, tighter bounds compared to previous methods.

Findings

Derived a computable QSL for open quantum systems

Provided examples demonstrating the effectiveness of the bounds

Showed the bounds are tighter than existing ones

Abstract

In recent years, Arenz et al. proposed the idea of reachable set characterization based on the quantum speed limit (QSL); that is, the reachable set of the target unitary gate in a closed qubit system can be characterized by considering the QSL as the necessary condition that the control setup must satisfy in order to achieve the goal. Inspired by this idea, in this paper we characterize a general Markovian open quantum system based on the QSL derived in \cite{Kohei2}. Note that this bound is not only explicitly computable with respect to system parameters, but also tighter than the other bounds. Some examples for demonstrating this analysis will be given.