Entanglement Degree of a Degenerate Two-Photon Process with Kerr-Like Medium
Mahmoud Abdel‐Aty, Shigeru Furuichi, M. S. Ateto · Japanese Journal of Applied Physics · 2002
In this study, we use the quantum entropy to measure the degree of entanglement in the time development of the two-level particle (atom or ion). The influence of atomic coherence on the evolution of the field quantum entropy and the entanglement of the atom-field in the two-photon process, taking into account the level shifts produced by the Stark effect with an additional Kerr-like medium for one mode, are examined. The exact results are employed to perform a careful investigation of the temporal evolution of the entropy. It is shown that the evolution of the field entropy is very sensitive to the relative phase of the particle and field. The effect of both the Stark shift and the presence of a Kerr-like medium on the entropy is analyzed. The results show that the effect of the Kerr-like medium and the Stark shift changes the quasiperiod of the field entropy evolution and the entanglement between the particle and the field. The general conclusions reached are illustrated by numerical results.