Atomphoton entanglement beyond the multiphoton resonance condition
Abstract
Atomphoton entanglement between the dressed atom and its spontaneous emission is studied in a neardegenerate threelevel Vtype atomic system in multiphoton resonance condition and beyond it. Taking into account the quantum interference due to the spontaneous emission, the density matrix equations of motion are numerically calculated in twophoton resonance condition and beyond it. The dynamical behavior of these two subsystems is investigated by using the von Neumann entropy. We apply the Floquet decomposition to the equations of motion to solve this timedependent problem and identify the contribution of the different scattering processes to the atomphoton entanglement. In addition, the impact of the various nonlinear effects on the atomphoton entanglement is introduced in twophoton resonance condition. It is shown that the degree of entanglement (DEM) can be controlled via the intensity and the detuning of the coupling field as well as the quantum interference induced by spontaneous emission. We find that vacuuminduced interference has a major role in phase sensitivity of the DEM; however, beyond the twophoton resonance condition the DEM does not depend on the relative phase of the applied fields. Our results can be used for quantum information processing via entanglement.
 Publication:

Quantum Information Processing
 Pub Date:
 January 2016
 DOI:
 10.1007/s1112801511689
 arXiv:
 arXiv:1503.00678
 Bibcode:
 2016QuIP...15..199K
 Keywords:

 Entanglement;
 Quantum interference;
 Quantum information;
 Physics  Atomic and Molecular Clusters;
 Quantum Physics
 EPrint:
 22 pages, 8 figures