Speeding up Thermalisation via Open Quantum System Variational Optimisation

TL;DR

This paper introduces a variational algorithm for optimizing the evolution of open quantum systems, specifically targeting the speedup of thermalisation processes in quantum systems.

Contribution

It derives a variational algorithm for Lindblad evolution in Liouville space and discusses its potential to accelerate thermalisation in open quantum systems.

Findings

Demonstrates control over qubit thermalisation using the variational approach

Proposes a method to evaluate potential speedup of thermalisation

Provides a framework for optimizing open quantum system dynamics

Abstract

Optimizing open quantum system evolution is an important step on the way to achieving quantum computing and quantum thermodynamic tasks. In this article, we approach optimisation via variational principles and derive an open quantum system variational algorithm explicitly for Lindblad evolution in Liouville space. As an example of such control over open system evolution, we control the thermalisation of a qubit attached to a thermal Lindbladian bath with a damping rate $\gamma$. Since thermalisation is an asymptotic process and the variational algorithm we consider is for fixed time, we present a way to discuss the potential speedup of thermalisation that can be expected from such variational algorithms.