Coherent trapping of the atomic population in a noncollinear-wave field

A.V. Tajchenachev, A.M. Tumajkin, Valeriy I. Yudin

Boris G. Matisov, I. E. Mazets, Laurentius Windholz

We consider the case of interaction of a three-level atom with a high intensity pulse electromagnetic field. Rabi frequencies are assumed to be of the order of the transition frequency or greater. We demonstrate that coherent population trapping exists even in such a case when the usual rotating-wave approximation is no longer valid. However, a certain condition on the phases of electromagnetic wave components has to be satisfied in order to make coherent population trapping possible. This condition is specific for the strong field case in contrast to the case where the rotating-wave approximation is valid. Also we point out some elements for which a model of an atom with a finite number of levels may still be valid while the rotating-wave approximation breaks down.

G. S. Agarwal, Kishore T. Kapale

We present an atom localization scheme based on coherent population trapping. We consider atomic transitions in a Lambda configuration where the control field is a standing-wave field. The probe field and the control field produce coherence between the two ground states and prepare the atom in a pure state. We show that the population in one of the ground states has the same fringe pattern as produced by a Fabry–Perot interferometer and thus measurement of this population would localize the atom. Interestingly enough the role of the cavity finesse is played by the ratio of the intensities of the pump and probe. This is in fact the reason for obtaining extreme subwavelength localization.

Jin-sheng Peng, Gao‐xiang Li

Boris G. Matisov, A. G. Chirkov, I. E. Mazets

We consider a case of interaction of a three-level atom with high-intensity electromagnetic field when the Rabi frequencies are greater than the atomic transition frequencies. We show that coherent population trapping can exist under the certain phase conditions in this case of the rotating wave approximation violation.