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: akhtarshenas@phys.ui.ac.ir khezrian.m@gmail.com
Received:
14
October
2009
Revised:
11
December
2009
Published online:
16
February
2010
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.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2010
