Generation of Entanglement between Two Two-Level Atoms Coupled to a Microtoroidal Cavity Via Thermal Field

Emilio H S Sousa,J A Roversi

doi:10.3390/quantum2030024

Abstract

We investigate the entanglement dynamics of a system comprising a pair of two-level dipole-dipole interacting atoms coupled to a microtoroidal resonator. Each atom is individually coupled with the two counter-propagating whispering gallery modes of the resonator through their evanescent fields. The atom-atom entanglement shown for several parameter sets of the system was obtained using the negativity. For ideal resonators, it is seen that the entanglement is correlated to the dipole-dipole interaction and the average number of photons when the modes of the resonator are prepared in a thermal state even at high temperatures. Further, for the non-ideal resonator case, where there is a small structural deformation of the microtoroidal structure that allows a direct coupling between the modes, a counter-intuitive result is presented. The imperfections also offer the advantage of generating maximally entangled states for a two-atom subsystem with maximum fidelity.

Highlights

Quantum entanglement represents a key resource for exploring quantum information processing, such as quantum cryptography [1], quantum computing [2], and quantum teleportation [3]
It would be interesting to investigate how the effects of the thermal field, at high temperatures, can be supplied through controllable parameters of the system for the maintenance of the entanglement, with high fidelity, between two two-level atoms coupled to a microtoroidal cavity
We have explored the entanglement dynamics between two identical two-level atoms interacting via dipole-dipole interaction and coupled simultaneously to the two whispering gallery modes (WGMs) microtoroidal resonator in the presence of a thermal field

Summary

Introduction

Quantum entanglement represents a key resource for exploring quantum information processing, such as quantum cryptography [1], quantum computing [2], and quantum teleportation [3]. It would be interesting to investigate how the effects of the thermal field, at high temperatures, can be supplied through controllable parameters of the system for the maintenance of the entanglement, with high fidelity, between two two-level atoms coupled to a microtoroidal cavity. We propose to study the generation of entanglement and quantum state transfer in a system comprising a pair of two-level dipole-dipole interacting atoms coupled to a microtoroidal resonator. In this case, the two atoms are individually coupled with the two WGMs of a microtoroidal resonator through their evanescent fields.

Theoretical Model

Entanglement Dynamics between the Two Atoms

Conclusions