Entanglement evolution of two remote and non-identical Jaynes-Cummings atoms

TL;DR

This paper analyzes how entanglement evolves between two remote, non-identical atoms in a double Jaynes-Cummings model, revealing conditions for entanglement transfer, sudden death, and conservation laws under various interactions.

Contribution

It provides a detailed analysis of entanglement dynamics in non-identical, remote atom-cavity systems, including effects of asymmetry and detuning on entanglement transfer and conservation.

Findings

Imperfect matching can enhance entanglement creation.

Full entanglement transfer is possible with specific initial states and couplings.

Detuning can prevent entanglement sudden death and enable complete transfer.

Abstract

A detailed treatment of the entanglement dynamics of two distant but non-identical systems is presented. We study the entanglement evolution of two remote atoms interacting independently with a cavity field, as in the double Jaynes-Cummings (JC) model. The four-qubit pairwise concurrences are studied, allowing for asymmetric atom-cavity couplings and off-resonant ineractions. Counter to intuition, imperfect matching can prove advantageous to entanglement creation and evolution. For two types of initial entanglement, corresponding to spin correlated and anti-correlated Bell states \Phi and \Psi, a full, periodic and directed transfer of entanglement into a specific qubit pair is possible, for resonant interactions, depending on the choice of relative couplings. Furthermore, entanglement transfer and sudden death (ESD) can be prevented using off-resonant interactions, although for some initial states, detunings will trigger an otherwise frozen entanglement, to allow a full entanglement transfer. We confirm a conservation rule governing the pairwise entanglement between the non-interacting systems, that for the initial state \Psi the sum of the square of these concurrences (SSC) is conserved. For \Phi, the total SSC is reduced periodically, even to zero in some cases, to reveal a complete and abrupt loss of all non-local pairwise entanglement.