Photon exchange and correlations transfer in atom-atom entanglement dynamics

TL;DR

This paper investigates how entanglement between two initially entangled atoms evolves over time within a quantum field theory framework, revealing phenomena like sudden death and revival unrelated to photon exchange, due to entanglement transfer between atoms and the field.

Contribution

It demonstrates that entanglement dynamics can occur without photon exchange, highlighting entanglement transfer mechanisms in atom-field systems using perturbative quantum field theory.

Findings

Entanglement sudden death and revival occur without photon exchange.

Entanglement transfer between atoms and the electromagnetic field explains these phenomena.

Similar entanglement dynamics are observed across different system partitions.

Abstract

We analyze the entanglement dynamics of a system composed by a pair of neutral two-level atoms that are initially entangled, and the electromagnetic field, initially in the vacuum state, within the formalism of perturbative quantum field theory up to the second order. We show that entanglement sudden death and revival can occur while the atoms remain spacelike-separated and therefore cannot be related with photon exchange between the atoms. We interpret these phenomena as the consequence of a transfer of atom-atom entanglement to atom-field entanglement and viceversa. We also consider the different bi-partitions of the system, finding similar relationships between their entanglement evolutions.