Eur. Phys. J. D 57, 271-279 (2010)
https://doi.org/10.1140/epjd/e2010-00025-8

Entanglement dynamics and decoherence of an atom coupled to a dissipative cavity field

¹ Department of Physics, University of Isfahan, Isfahan, Iran
² Quantum Optics Group, University of Isfahan, Isfahan, Iran

Corresponding authors: This email address is being protected from spambots. You need JavaScript enabled to view it. This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 14 October 2009
Revised: 11 December 2009
Published online: 16 February 2010

Abstract

In this paper, we investigate the entanglement dynamics and decoherence in the interacting system of a strongly driven two-level atom and a single mode vacuum field in the presence of dissipation for the cavity field. Starting with an initial product state with the atom in a general pure state and the field in a vacuum state, we show that the final density matrix is supported on space, and therefore, the concurrence can be used as a measure of entanglement between the atom and the field. The influences of the cavity decay on the quantum entanglement of the system are also discussed. We also examine the Bell-CHSH violation between the atom and the field and show that there are entangled states for which the Bell-BCSH inequality is not violated. Using the above system as a quantum channel, we also investigate the quantum teleportation of a generic qubit state and also a two-qubit entangled state, and show that in both cases the atom-field entangled state can be useful to teleport an unknown state with fidelity better than any classical channel.