Dynamical stability of entanglement between spin ensembles

TL;DR

This paper investigates the stability of entanglement between two spin ensembles in a noisy environment, demonstrating that macroscopic entangled states can persist under certain conditions, which is promising for quantum memory applications.

Contribution

It provides a comparative analysis of entanglement stability in single versus coupled spin ensembles within a Markovian bath, highlighting conditions for stable macroscopic entanglement.

Findings

Macroscopic entangled states can stably exist in a common bath.

Entanglement robustness is analyzed via linear entropy growth.

Results suggest potential for stable quantum memory in noisy environments.

Abstract

We study the dynamical stability of the entanglement between the two spin ensembles in the presence of an environment. For a comparative study, we consider the two cases: a single spin ensemble, and two ensembles linearly coupled to a bath, respectively. In both circumstances, we assume the validity of the Markovian approximation for the bath. We examine the robustness of the state by means of the growth of the linear entropy which gives a measure of the purity of the system. We find out macroscopic entangled states of two spin ensembles can stably exist in a common bath. This result may be very useful to generate and detect macroscopic entanglement in a common noisy environment and even a stable macroscopic memory.