Buffer-Gas Cooled Bose-Einstein Condensate

摘要

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 (~4He~*) 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 μK 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.