title: Non-Abelian gauge potentials for ultracold atoms with degenerate dark states.
abstract: We show that the adiabatic motion of ultracold, multilevel atoms in spatially varying laser fields can give rise to effective non-Abelian gauge fields if degenerate adiabatic eigenstates of the atom-laser interaction exist. A pair of such degenerate dark states emerges, e.g., if laser fields couple three internal states of an atom to a fourth common one under pairwise two-photon-resonance conditions. For this so-called tripod scheme we derive general conditions for truly non-Abelian gauge potentials and discuss special examples. In particular we show that using orthogonal laser beams with orbital angular momentum an effective magnetic field can be generated that has a monopole component.
authors.affiliation: Institute of Theoretical Physics and Astronomy of Vilnius University, A. Gostauto 12, 01108 Vilnius, Lithuania.
authors.forename: J
authors.initials: J
authors.lastname: Ruseckas
authors.forename: G
authors.initials: G
authors.lastname: Juzeliūnas
authors.forename: P
authors.initials: P
authors.lastname: Ohberg
authors.forename: M
authors.initials: M
authors.lastname: Fleischhauer