Theory of an atomic beam splitter based on velocity-tuned resonances

Abstract
We develop the theory of an atomic beam splitter in which a monoenergetic beam of two-level atoms is incident normally to a classical standing-wave light field. The incident atomic wave function can be split into two coherent components with transverse momenta ±(2n+1)ħk using velocity-tuned resonances, where n is the order of the resonance. We discuss the cases of zero- and first-order resonances in detail, and show that the velocity-tuned resonances are renormalized due to a high-frequency Stark shift. Numerical results that display the effects of a finite momentum spread in the incident atomic beam are presented.