Cavity-based architecture to preserve quantum coherence and entanglement

TL;DR

This paper presents a cavity-based environmental architecture that can switch between Markovian and non-Markovian regimes, enabling indefinite preservation of quantum coherence and significantly extending entanglement lifetimes in quantum systems.

Contribution

The study introduces a simple cavity architecture that controls quantum resource dynamics, allowing indefinite coherence preservation and enhanced entanglement lifetimes, with practical feasibility in circuit QED.

Findings

Quantum coherence can be preserved indefinitely with a perfect cavity.

Entanglement lifetimes can be extended by orders of magnitude.

The architecture is scalable and feasible with current experimental parameters.

Abstract

Quantum technology relies on the utilization of resources, like quantum coherence and entanglement, which allow quantum information and computation processing. This achievement is however jeopardized by the detrimental effects of the environment surrounding any quantum system, so that finding strategies to protect quantum resources is essential. Non-Markovian and structured environments are useful tools to this aim. Here we show how a simple environmental architecture made of two coupled lossy cavities enables a switch between Markovian and non-Markovian regimes for the dynamics of a qubit embedded in one of the cavity. Furthermore, qubit coherence can be indefinitely preserved if the cavity without qubit is perfect. We then focus on entanglement control of two independent qubits locally subject to such an engineered environment and discuss its feasibility in the framework of circuit quantum electrodynamics. With up-to-date experimental parameters, we show that our architecture allows entanglement lifetimes orders of magnitude longer than the spontaneous lifetime without local cavity couplings. This cavity-based architecture is straightforwardly extendable to many qubits for scalability.