Bose-Einstein condensation of atoms in a uniform potential

TL;DR

This paper reports the first observation of Bose-Einstein condensation in a uniform potential, confirming theoretical predictions and opening new avenues for studying many-body physics.

Contribution

It demonstrates Bose-Einstein condensation in a uniform optical box trap, validating theoretical models and contrasting with traditional harmonic traps.

Findings

Condensation observed in a uniform potential with bimodal momentum distribution

Critical temperature matches theoretical predictions for uniform gases

Coherence confirmed through matter-wave interference

Abstract

We have observed Bose-Einstein condensation of an atomic gas in the (quasi-)uniform three-dimensional potential of an optical box trap. Condensation is seen in the bimodal momentum distribution and the anisotropic time-of-flight expansion of the condensate. The critical temperature agrees with the theoretical prediction for a uniform Bose gas. The momentum distribution of our non-condensed quantum-degenerate gas is also clearly distinct from the conventional case of a harmonically trapped sample and close to the expected distribution in a uniform system. We confirm the coherence of our condensate in a matter-wave interference experiment. Our experiments open many new possibilities for fundamental studies of many-body physics.