Surface Effects in Magnetic Microtraps

TL;DR

This study explores how surface proximity affects Bose-Einstein condensates and ultra cold atoms in magnetic microtraps, revealing reduced lifetimes, weak thermal coupling, and condensate fragmentation near surfaces.

Contribution

It provides detailed measurements of atom lifetime, heating rates, and condensate fragmentation as a function of distance to a magnetic surface, highlighting surface-induced effects.

Findings

Atom lifetime decreases linearly with surface proximity.

Weak thermal coupling with heating rates below 500 nK/s.

Observation of periodic condensate fragmentation near surfaces.

Abstract

We have investigated Bose-Einstein condensates and ultra cold atoms in the vicinity of a surface of a magnetic microtrap. The atoms are prepared along copper conductors at distances to the surface between 300 um and 20 um. In this range, the lifetime decreases from 20 s to 0.7 s showing a linear dependence on the distance to the surface. The atoms manifest a weak thermal coupling to the surface, with measured heating rates remaining below 500 nK/s. In addition, we observe a periodic fragmentation of the condensate and thermal clouds when the surface is approached.