Sub-Doppler laser cooling of $^{39}$K via the 4S$\to$5P transition
Govind Unnikrishnan, Michael Gröbner, Hanns-Christoph Nägerl
SciPost Phys. 6, 047 (2019) · published 18 April 2019
- doi: 10.21468/SciPostPhys.6.4.047
- Submissions/Reports
Abstract
We demonstrate sub-Doppler laser cooling of $ ^{39} $K using degenerate Raman sideband cooling via the 4S$_{1/2} \rightarrow $5P$ _{1/2} $ transition at 404.8 nm. By using an optical lattice in combination with a magnetic field and optical pumping beams, we obtain a spin-polarized sample of up to $5.6 \times 10^{7}$ atoms cooled down to a sub-Doppler temperature of 4 $\mu $K, reaching a peak density of $3.9 \times 10^{9}$ atoms/cm$ ^{3} $, a phase-space density greater than $ 10^{-5} $, and an average vibrational level of $ \langle \nu \rangle=0.6 $ in the lattice. This work opens up the possibility of implementing a single-site imaging scheme in a far-detuned optical lattice utilizing shorter wavelength transitions in alkali atoms, thus allowing improved spatial resolution.
Cited by 4
Authors / Affiliations: mappings to Contributors and Organizations
See all Organizations.- 1 2 Govind Unnikrishnan,
- 1 2 Michael Gröbner,
- 1 2 Hanns-Christoph Nägerl
- 1 Institut für Experimentalphysik, Universität Innsbruck
- 2 Universität Innsbruck / University of Innsbruck [UBI]
- Austrian Science Fund (FWF) (through Organization: Fonds zur Förderung der wissenschaftlichen Forschung / FWF Austrian Science Fund [FWF])
- European Research Council [ERC]