Engineering of Quantum State by Time-Dependent Decoherence-Free Subspaces

TL;DR

This paper introduces a novel method for quantum-state engineering using time-dependent decoherence-free subspaces, ensuring unitary evolution and robustness against decoherence even with imperfect controls, suitable for practical quantum technologies.

Contribution

The paper presents a new approach applying time-dependent decoherence-free subspaces to achieve robust, unitary quantum-state engineering in open quantum systems, overcoming limitations of previous methods.

Findings

Quantum-state purity remains high during the process.

The method resists decoherence even with imperfect controls.

Suitable for multitask quantum-state engineering applications.

Abstract

We apply the time-dependent decoherence-free subspace theory to a Markovian open quantum system in order to present a novel proposal for quantum-state engineering program. By quantifying the purity of the quantum state, we verify that the quantum-state engineering process designed via our method is completely unitary within any total engineering time. Even though the controls on the open quantum system are not perfect, the asymptotic purity is still robust. Owing to its ability to completely resist decoherence and the lack of restraint in terms of the total engineering time, our proposal is suitable for multitask quantum-state engineering program. Therefore, this proposal is not only useful for achieving the quantum-state engineering program experimentally, it also helps us build both a quantum simulation and quantum information equipment in reality.