Scattering of two-level atoms by delta lasers: exactly solvable models in atom optics

We study the scattering of two-level atoms at narrow laser fields, modelled by a δ-shape intensity profile. The unique properties of these potentials allow us to give simple analytic solutions for one or two field zones. Several applications are studied: a single δ-laser may serve as a model for atom detection and arrival-time measurements, either by means of fluorescence or variations in occupation probabilities. We show that, in principle, this ideal detector can measure the particle density, the quantum mechanical flux, arrival-time distributions or local kinetic energy densities. Moreover, two spatially separated δ-lasers are used to investigate quantized-motion effects in Ramsey interferometry.