Measurement of the trapping lifetime close to a cold metallic surface on a cryogenic atom-chip

Andreas Emmert (1) , Adrian Lupascu (1) , Gilles Nogues (1) , Michel Brune (1) , Jean-Michel Raimond (1) , Serge Haroche (1, 2)

1 LKB (Lhomond) - Laboratoire Kastler Brossel
2 LKB [Collège de France] - Laboratoire Kastler Brossel

We have measured the trapping lifetime of magnetically trapped atoms in a cryogenic atom-chip experiment. An ultracold atomic cloud is kept at a fixed distance from a thin gold layer deposited on top of a superconducting trapping wire. The lifetime is studied as a function of the distances to the surface and to the wire. Different regimes are observed, where loss rate is determined either by the technical current noise in the wire or the Johnson-Nyquist noise in the metallic gold layer, in good agreement with theoretical predictions. Far from the surface, we observe exceptionally long trapping times for an atom-chip, in the 10-minutes range.

Mots clés: ultracold atoms; superconductor; atom-chip; Johnson-Nyquist noise; cryogenic temperature; trapping lifetime; magnetic trap

Domaines: Physique Atomique [physics.atom-ph]

Andreas Emmert, Adrian Lupascu, Gilles Nogues, Michel Brune, Jean-Michel Raimond, et al.. Measurement of the trapping lifetime close to a cold metallic surface on a cryogenic atom-chip. The European Physical Journal D : Atomic, molecular, optical and plasma physics, 2009, 51, pp.173-177. ⟨10.1140/epjd/e2009-00001-5⟩. ⟨hal-00356575⟩