title: Nanoscale "Dark State" Optical Potentials for Cold Atoms.
abstract: We discuss the generation of subwavelength optical barriers on the scale of tens of nanometers, as conservative optical potentials for cold atoms. These arise from nonadiabatic corrections to Born-Oppenheimer potentials from dressed "dark states" in atomic Λ configurations. We illustrate the concepts with a double layer potential for atoms obtained from inserting an optical subwavelength barrier into a well generated by an off-resonant optical lattice, and discuss bound states of pairs of atoms interacting via magnetic dipolar interactions. The subwavelength optical barriers represent an optical "Kronig-Penney" potential. We present a detailed study of the band structure in optical Kronig-Penney potentials, including decoherence from spontaneous emission and atom loss to open "bright" channels.
authors.affiliation: Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020 Innsbruck, Austria.|Institute for Theoretical Physics, University of Innsbruck, A-6020 Innsbruck, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Łącki
authors.affiliation: Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020 Innsbruck, Austria.|Institute for Theoretical Physics, University of Innsbruck, A-6020 Innsbruck, Austria.
authors.forename: M A
authors.initials: MA
authors.lastname: Baranov
authors.affiliation: Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020 Innsbruck, Austria.|Institute for Theoretical Physics, University of Innsbruck, A-6020 Innsbruck, Austria.|ITAMP, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138, USA.|Physics Department, Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138, USA.
authors.forename: H
authors.initials: H
authors.lastname: Pichler
authors.affiliation: Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020 Innsbruck, Austria.|Institute for Theoretical Physics, University of Innsbruck, A-6020 Innsbruck, Austria.
authors.forename: P
authors.initials: P
authors.lastname: Zoller