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

TL;DR

This study measures how long ultracold atoms can be trapped near a cryogenic metallic surface, revealing different loss mechanisms and achieving exceptionally long trapping times, which are promising for quantum technologies.

Contribution

It provides the first detailed measurement of atom trapping lifetimes near a cryogenic metallic surface, confirming theoretical noise models and demonstrating long trapping durations.

Findings

Loss rates depend on distance and noise sources.

Different regimes are identified based on dominant noise.

Trapping times up to 10 minutes are achieved.

Abstract

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.