Sub-Doppler cooling of sodium atoms in gray molasses
Authors: Colzi G., Durastante G., Fava E., Serafini S., Lamporesi G., Ferrari G.
Autors Affiliation: 1 INO-CNR BEC Center and Dipartimento di Fisica, Universit`a di Trento, 38123 Povo, Italy
2 Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
Abstract: We report on the realization of sub-Doppler laser cooling of sodium atoms in gray molasses using the D1 optical transition (3s 2
S1/2 → 3p 2P1/2) at 589.8 nm. The technique is applied to samples containing 3 × 10^9 atoms, previously cooled to 350 μK in a magneto-optical trap, and it leads to temperatures as low as 9 μK and
phase-space densities in the range of 10^−4. The capture efficiency of the gray molasses is larger than 2/3, and we observe no density-dependent heating for densities up to 10^11 cm^−3.
Journal/Review: PHYSICAL REVIEW A
Volume: 93 Pages from: 023421-1 to: 023421-6
KeyWords: laser cooling; sodium; gray molasses