Longitudinal Atom Interferometry

A detuned, radiofrequency field interacting with atoms in an atomic beam constitutes a beamsplitter in longitudinal momentum space. Using such beamsplitters, we have constructed a longitudinal atom interferometer in a generalization of Ramsey's classic SOF configuration. This interferometer is well-suited to studying the longitudinal coherence properties of matter-wave beams. We report on two such experiments, including a deconvolution of the longitudinal density matrix of an atomic beam, and a search for longitudinal coherences coming from our supersonic beam source.