Bose-Einstein condensates near a microfabricated surface

TL;DR

This study compares Bose-Einstein condensates near microfabricated surfaces using magnetic and optical traps, revealing differences in fragmentation and lifetime limitations due to technical noise.

Contribution

It demonstrates that condensate fragmentation occurs in magnetic traps but not in optical traps at the same location, and identifies technical noise as a factor affecting lifetime.

Findings

Condensate lifetime ≥ 20 seconds, independent of atom-surface distance.

Fragmentation observed in magnetic traps but not in optical traps.

Radio-frequency spin-flip transitions caused by technical noise were detected.

Abstract

Magnetically and optically confined Bose-Einstein condensates were studied near a microfabricated surface. Condensate fragmentation observed in microfabricated magnetic traps was not observed in optical dipole traps at the same location. The measured condensate lifetime was $\geq 20$ s and independent of the atom-surface separation under both magnetic and optical confinement. Radio-frequency spin-flip transitions driven by technical noise were directly observed for optically confined condensates and could limit the condensate lifetime in microfabricated magnetic traps.