Atom-optics approach to studying transport phenomena

We present a simple experimental scheme, based on standard atom-optics techniques, to design highly versatile model systems for the study of single-particle quantum transport phenomena. The scheme is based on a discrete set of free-particle momentum states that are coupled via momentum-changing two-photon Bragg transitions, driven by pairs of interfering laser beams. In the effective lattice models that are accessible, this scheme allows for single-site detection, as well as site-resolved and dynamical control over all system parameters. We discuss two possible implementations, based on state-preserving Bragg transitions and on state-changing Raman transitions, which, respectively, allow for the study of nearly arbitrary single-particle Abelian U(1) and non-Abelian U(2) lattice models.