Longitudinal atom optics using localized oscillating fields: A fully quantum-mechanical treatment

We provide a fully quantal treatment of a beam of two-state particles inter acting with temporally oscillating potentials, and propose a number of long itudinal atom optics devices. A single oscillatory potential, in coupling t he two internal states, generally entangles each with a different longitudi nal momentum. An oscillatory potential can also act as an amplitude modulat or, creating momentum coherences within a single internal state. Two succes sive oscillatory fields (DSOF's), if differentially detuned, can couple an initially monochromatic state to a coherent momentum superposition, or alte rnatively may be used to detect a pre-existing momentum superposition. DSOF 's can create amplitude modulation which, despite the presence of a broad v elocity distribution, rephases at a selected distance downstream of the dev ice. Phase modulation generates coherent momentum sidebands which can evolv e into amplitude modulation at a particular location downstream. [S1050-294 7(99)05906-5].