Visualization of superposition states and Raman processes with two-dimensional atomic deflection

Abstract

The deflection of atoms in a $\ensuremath{\Lambda}$-type configuration passing through two crossed standing light waves is proposed for the probing and visualization of atomic superposition states. For this goal, we use both the large-dispersive and Raman-resonant regimes of atom-field interaction, giving rise to position-dependent phase shifts of fields, and perform double simultaneous spatial measurements on an atom. In this way, it is demonstrated that the deflection spatial patterns of atoms in a $\ensuremath{\Lambda}$-configuration passing through modes of standing waves are essentially modified if the atoms are initially prepared in coherent superpositions of their low-level states as well as when the superposition states are created during the process of deflection. There are similar results for the joint momentum distributions of atoms. Furthermore, considering both one-photon- and two-photon-excitation regimes of $\ensuremath{\Lambda}$ atoms, we also illustrate that the two-dimensional patterns of defected atoms qualitatively reflect the efficiency of the Raman processes.