Sub-Doppler laser cooling of fermionic 40K atoms in three-dimensional gray optical molasses

TL;DR

This paper demonstrates a fast and efficient sub-Doppler laser cooling technique for fermionic 40K atoms using gray molasses, significantly reducing temperature and increasing phase space density for potential applications in quantum gases.

Contribution

It introduces a novel gray molasses cooling scheme for 40K atoms on the D_1 transition, achieving rapid cooling to ultracold temperatures.

Findings

Reduced atom temperature from ~4 μK to 20 μK in 8 ms

Achieved a phase space density of ~10^-5

Demonstrated potential for fast evaporation of fermionic 40K

Abstract

We demonstrate sub-Doppler cooling of 40K on the D_1 atomic transition. Using a gray molasses scheme, we efficiently cool a compressed cloud of 6.5x10^8 atoms from ~ 4\mK to 20uK in 8 ms. After transfer in a quadrupole magnetic trap, we measure a phase space density of ~10^-5. This technique offers a promising route for fast evaporation of fermionic 40K.