title: Intrinsic photoconductivity of ultracold fermions in optical lattices.
abstract: We report on the experimental observation of an analog to a persistent alternating photocurrent in an ultracold gas of fermionic atoms in an optical lattice. The dynamics is induced and sustained by an external harmonic confinement. While particles in the excited band exhibit long-lived oscillations with a momentum-dependent frequency, a strikingly different behavior is observed for holes in the lowest band. An initial fast collapse is followed by subsequent periodic revivals. Both observations are fully explained by mapping the system onto a nonlinear pendulum.
authors.affiliation: Institut für Laser-Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Heinze
authors.forename: J S
authors.initials: JS
authors.lastname: Krauser
authors.forename: N
authors.initials: N
authors.lastname: Fläschner
authors.forename: B
authors.initials: B
authors.lastname: Hundt
authors.forename: S
authors.initials: S
authors.lastname: Götze
authors.forename: A P
authors.initials: AP
authors.lastname: Itin
authors.forename: L
authors.initials: L
authors.lastname: Mathey
authors.forename: K
authors.initials: K
authors.lastname: Sengstock
authors.forename: C
authors.initials: C
authors.lastname: Becker
mesh_terms: D003080:Cold Temperature; D004601:Elementary Particles; D055096:Optical Devices; D011789:Quantum Theory