Person:

Connolly, Colin

We report the creation of a Bose-Einstein condensate using buffer-gas cooling, the first realization of Bose-Einstein condensation using a broadly general method which relies neither on laser cooling nor unique atom-surface properties. Metastable helium ((^4)He*) is buffer-gas cooled, magnetically trapped, and evaporatively cooled to quantum degeneracy. 10(^{11}) atoms are initially trapped, leading to Bose-Einstein condensation at a critical temperature of (5 \mu K) and threshold atom number of 1.1×10(^6). This method is applicable to a wide array of paramagnetic atoms and molecules, many of which are impractical to laser cool and impossible to surface cool.

Metastable helium is buffer gas cooled, magnetically trapped, and evaporatively cooled in large numbers. 1011 4 He* atoms are trapped at an initial temperature of 400 mK and evaporatively cooled into the ultracold regime, resulting in a cloud of 2± 0.5 109 atoms at 1.4± 0.2 mK. Efficient evaporation indicates low collisional loss for 4 He* in both the ultracold and multi-partial-wave regime, in agreement with theory.