Creation of a Bose-condensed gas of 87Rb by laser cooling
Abstract
Protocols for attaining quantum degeneracy in atomic gases almost exclusively rely on evaporative cooling, a time-consuming final step associated with substantial atom loss. We demonstrate direct laser cooling of a gas of rubidium-87 (87Rb) atoms to quantum degeneracy. The method is fast and induces little atom loss. The atoms are trapped in a two-dimensional optical lattice that enables cycles of compression to increase the density, followed by Raman sideband cooling to decrease the temperature. From a starting number of 2000 atoms, 1400 atoms reach quantum degeneracy in 300 milliseconds, as confirmed by a bimodal velocity distribution. The method should be broadly applicable to many bosonic and fermionic species and to systems where evaporative cooling is not possible.
- Publication:
-
Science
- Pub Date:
- November 2017
- DOI:
- 10.1126/science.aan5614
- arXiv:
- arXiv:1705.03421
- Bibcode:
- 2017Sci...358.1078H
- Keywords:
-
- PHYSICS;
- Physics - Atomic Physics;
- Condensed Matter - Quantum Gases
- E-Print:
- 5 pages, 3 figures (main text)