Dynamics of entanglement between two free atoms with quantized motion

TL;DR

This paper investigates how the quantum motion of two free atoms influences their electronic entanglement, revealing a transition between different reservoir interactions, entanglement sudden death and birth, and the formation of a stationary dark state.

Contribution

It introduces a model that accounts for atomic motion effects on entanglement dynamics, showing a continuous transition between common and independent reservoir behaviors.

Findings

Entanglement exhibits sudden death and birth depending on atomic separation.

A stationary dark state with persistent entanglement can form from separable states.

The transition between reservoir types depends on inter-atomic distance and localization.

Abstract

The electronic entanglement between two free atoms initially at rest is obtained including the effects of photon recoil, for the case when quantum dispersion can be neglected during the atomic excited-state lifetime. Different from previous treatments using common or statistically independent reservoirs, a continuous transition between these limits is observed, that depends on the inter-atomic distance and degree of localization. The occurrence of entanglement sudden death and birth as predicted here deviates from the case where the inter-atomic distance is treated classically by a static value. Moreover, the creation of a dark state is predicted, which manifests itself by a stationary entanglement that even may be created from an initially separable state.