Reflection beam splitter for multilevel atoms

We propose a beam splitter for atomic de Broglie waves combining atomic reflection from an evanescent laser wave with induced transitions between ground-state sublevels in a homogeneous magnetic field. An inelastic change of Zeeman energy during the reflection results in an angular separation of the outgoing partial beams. By choosing suitable relative phases between the polarization components of the evanescent wave, a two-channel beam splitter with an adjustable splitting ratio can be realized.