Berlin 2005 – wissenschaftliches Programm
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Q: Quantenoptik und Photonik
Q 2: Poster Quantengase
Q 2.18: Poster
Freitag, 4. März 2005, 11:00–12:30, Poster HU
Cold Atoms above Microfabricated Substrates and Atom-Atom Interaction under Tight Cylindrical Confinement. — •Ji il Kim1, Peter Schmelcher2, and Jörg Schmiedmayer1 — 1Physikalisches Institut, Universität Heidelberg — 2Theoretische Chemie, Universität Heidelberg
Surface micro-traps have increased our ability to manipulate cold neutral atoms. Charged and mainly current carrying conductors are patterned on a substrate with micro- and even nano-meter precision with thin-film technologies. The small scale electric and magnetic potentials from such conductors can be generally very steep, well defined, and showing great versatility. With these surface micro-traps, or first examples of possible "Atom Chips", one can probe with cold atoms a wide set of phenomena for which an essential feature is the quantum behavior in very small dimensions. Singling out one specific example, we mention here the atomic behavior in an atom-waveguide or in a very elongated trap. Under tight cylindrical confinement, the interaction of cold atoms can be different from free space. Assessment of this difference is necessary to better understand the atomic guiding or trapping. In our treatment, the effective 1D amplitude for the atom-atom scattering along the cylindrical axis of the confinement is decomposed in terms of angular momentum scattering phase-shifts, related to a general three dimensional interaction potential V(r). Both the symmetric and antisymmetric parts of the wave function describing bosons and fermions can then show strong resonances corresponding to an infinitly strong repulsive or attractive effective interaction.