# Entanglement dynamics of two two-level atoms in the vicinity of an invisibility cloak

## TL;DR

This paper investigates how an invisibility cloak affects the entanglement dynamics of two two-level atoms, revealing that the cloak's effectiveness varies with frequency and is compromised near resonance.

## Contribution

It presents a quantum electrodynamics framework to analyze entanglement evolution near an invisibility cloak, highlighting frequency-dependent cloaking performance.

## Key findings

- Entanglement is generated via spontaneous emission and dipole-dipole interaction.
- Cloak effectiveness diminishes near resonance frequency.
- Atoms remain unentangled initially but become correlated over time.

## Abstract

We study the entanglement between two identical two-level atoms located near an ideal model of invisibility cloaks, by monitoring the the time evolution of the concurrence measure. We obtain the reduced density operator of the atomic subsystem based on a canonical quantization scheme presented for the electromagnetic field interacting with atomic systems in the presence of an anisotropic, inhomogeneous and absorbing magnetodielectric medium. It is shown that two atoms, which are prepared initially in an unentangled state, are correlated in weak coupling regime via the spontaneous emission and the dipole-dipole interaction of two atoms mediated by the invisibility cloak. We therefore find that the invisibility cloak, independent of the hidden object, works fairly well at frequencies far from the resonance frequency of the object and the cloak, whereas near the resonance frequency, the hidden object becoming detectable due to a sharp reduction of the concurrence.