Efficient demagnetization cooling of atoms and its limits

作者：Volchkov Valentin V^*; Ruehrig Jahn; Pfau Tilman; Griesmaier Axel

来源：Physical Review A, 2014, 89(4): 043417.

DOI：10.1103/PhysRevA.89.043417

Demagnetization cooling relies on spin-orbit coupling that brings motional and spin degrees of freedom into thermal equilibrium. In the case of a gas, one has the advantage that the spin degree of freedom can be cooled very efficiently using optical pumping. We investigate demagnetization cooling of a chromium gas in a deep optical dipole trap over a large temperature range and reach high densities up to 5 x 10(19) m(-3). We study the loss mechanism under such extreme conditions and identify excited-state collisions as the main limiting process. We discuss that in some systems demagnetization cooling has a realistic potential of reaching degeneracy by optical cooling only.

• 出版日期2014-4-17