Coherence of Light Fields

Dilawar Ali, Muhammad Umer Iftikhar, Muqaddar Abbas +1 more

Abstract A cold atomic medium (Rydberg medium) with cascade configuration under the blockade mechanism is considered. A partial coherent light (PCL) beam is incident on the medium, which makes an angle θ with z-axis. We study the influence of PCL field on the transmission spectrum and find high transmission of probe field for PCL field. Conversely, it is investigated that the transparency of probe field decrease for coherent light field. The transmission of probe field is also studied via beam width of PCL field and investigated high transmission of probe field for small beam width and vice versa. Interestingly, the Goos-Hänchen shift (GHS) in the transmitted light (TL) is studied for PCL field. Large negative and positive GHS in the TL are investigated for PCL field and small beam width of PCL field.

Ingolf Volker Hertel, Claus-Peter Schulz

Wu Shu

The field entropy evolution in a system of the Schrodinger cat state light field interacting with a two-level atom was studied by solving Milburn equation.The influence of intrinsic decoherence,the strength of light field and the phase angle between the two coherence states on the field entropy evolution was discussed.The results show that the field entropy vibration will be weak gradually because of the intrinsic decoherence,and the degree of entanglement in the field-atom system approaches to a certain value with time evolution.Furthermore,the degree of entanglement in the field-atom system only depends on the strength of light field and the phase angle between the two coherence states,and have nothing to do with intrinsic decoherence.When the strength of light field is relatively small,the degree of entanglement is maximum in a system of a two-level atom interacting with an odd coherence state light field,and it is minimum in a system of a two-level atom interacting with an even coherence state light field;it is intermediate for a system of a two-level atom interacting with Yurke-Stoler coherence state light field.When the intrinsic decoherence is fixed and the strength of light field is relatively large,the degree of entanglement in the field-atom system existing in the Yurke-stoler,the even coherence state and odd coherence state tends to the same.

Olga Korotkova, Greg Gbur

Zhang Ying-Jie, Yun‐Jie Xia, Ren Ting-Qi +3 more

A two-level atom drvien by a strong classical field interacts with a single-mode light field, and the interaction between the atom and the light field can turn into an effective anti-Jaynes-Cummings model under the conditions of strong driving and large detuning. In this paper, we mainly study the two-mode entangled coherent light field in this model, in which one mode of the entangled coherent light field interacts with a two-level atom driven by a strong classical field. During the evolution of the total system, we make a selective measurement on the atom. Through tuning the evolution time and the parameter of the coherent field, we can easily control the quantum statistical properties of the other mode of the entangled light fields and generate the expected non-classical light field in a longer interaction time and a wider region of coherent parameter.