Atomic Systems

Rahul Sawant, S. A. Rangwala

The control of light transmission through a standing-wave Fabry-P\'erot cavity containing atoms is theoretically and numerically investigated, when the cavity mode beam and an intersecting control beam are both close to specific atomic resonances. A four-level atomic system is considered and its interaction with the cavity mode is studied by solving for the cavity field and atomic state populations. The conditions for optical bistability of the atom-cavity system are obtained. The response of the intracavity intensity to an intersecting beam on atomic resonance is understood in the presence of stationary atoms (closed system) and nonstatic atoms (open system) in the cavity. The nonstatic system of atoms is modelled by adjusting the atomic state populations to represent the exchange of atoms in the cavity mode, which corresponds to a thermal environment where atoms are moving in and out of the cavity mode volume. The control behavior with three- and two-level atomic systems is also studied, and the rich physics arising out of these systems for closed and open atomic systems is discussed. The solutions to the models are used to interpret the steady-state and transient behavior observed by Sharma et al. [Phys. Rev. A 91, 043824 (2015)].

Walter E Thirring

Yabin Dong, Junyan Li, Zhiying Zhou

The electromagnetically induced grating effect in thermal and cold atoms has been studied theoretically. Studies have shown that, by adjusting the parameters, the first-order diffraction efficiency of the probe beam in the cold atomic system and the thermal atomic system is 34% and 31%, respectively, which is very close to the ideal diffraction efficiency of the sinusoidal grating. However, it is more difficult to prepare the cold atomic system than to prepare the thermal atomic system in the practical application, so the study of the electromagnetically induced grating effect in the thermal atomic system may be helpful for practical applications.

José Tito Mendonça, Hugo Terças

A.‐S. F. Obada, H. A. Hessian, Mostafa Hashem

We investigate the quantum entanglement in a system of two moving atoms interacting with a single mode field. An analytical solution for this system is obtained when both atoms are initially in the excited state and the field is in a coherent state. We study the effects of atomic motion and other parameters on the entanglement of the system and different bipartite partitions of the system (field–two atoms, atom–(field+atom)) through the tangles. The effect of atomic motion on the amount of entanglement between atoms and the field is also evaluated through the negativity. The results show that atomic motion leads to the periodic death and anabiosis of the entanglement between two moving atoms, and the time of the death and the amplitude of the anabiosis of the entanglement between two moving atoms depend on the coupling constant of two moving atoms and the parameter of the mode field.