Sisyphus Cooling of Lithium

Abstract

Laser cooling to sub-Doppler temperatures by optical molasses is thought to be inhibited in atoms with unresolved, near-degenerate hyperfine structure in the excited state. We demonstrate that such cooling is possible in one to three dimensions, not only near the standard D2 line for laser cooling, but over a range extending to the D1 line. Via a combination of Sisyphus cooling followed by adiabatic expansion, we reach temperatures as low as 40 μK, which corresponds to atomic velocities a factor of 2.6 above the limit imposed by a single photon recoil. Our method requires modest laser power at a frequency within reach of standard frequency locking methods. It is largely insensitive to laser power, polarization and detuning, magnetic fields, and initial hyperfine populations. Our results suggest that optical molasses should be possible with all alkali species.

5 pages, 3 figures

References in corpus (8)

• Single-Atom Resolved Fluorescence Imaging of an Atomic Mott Insulator
• Ultracold Heteronuclear Fermi-Fermi Molecules
• Λ-enhanced Sub-Doppler Cooling of Lithium Atoms in D1 Gray Molasses
• Formation of Ultracold Fermionic NaLi Feshbach Molecules
• Formation of ultracold LiCs molecules
• Feshbach resonances in mixtures of ultracold ${}^6$Li and ${}^{87}$Rb gases
• Feshbach resonances in an ultracold ${}^7$Li and ${}^{87}$Rb mixture
• Dynamics of Feshbach Molecules in an Ultracold Three-Component Mixture

Cited by in corpus (11)

• Site-resolved Imaging of Fermionic Lithium-6 in an Optical Lattice
• Efficient all-optical production of large ${}^6$Li quantum gases using D${}_1$ gray-molasses cooling
• Simultaneous sub-Doppler laser cooling of fermionic ${}^6$Li and ${}^{40}$K on the D${}_1$ line: Theory and Experiment
• Methods for Preparing Quantum Gases of Lithium
• Experimental Realization of a Relativistic Harmonic Oscillator
• Two-stage magneto-optical trapping and narrow-line cooling of ${}^6$Li atoms to high phase-space density
• Sub-Doppler laser cooling of 40K with Raman gray molasses on the D2 line
• Recoil-sensitive lithium interferometer without a subrecoil sample
• Photo-induced SU(3) topological material of spinless fermions
• Bimodal momentum distribution of laser-cooled atoms in optical lattices
• The neutron returning time in a linear potential