Efficient demagnetization cooling of atoms and its limits

• Main Authors: Volchkov, Valentin V, Rührig, Jahn, Pfau, Tilman, Griesmaier, Axel
• Format: Journal Article
• Language: English
• Published: 25-05-2014
• Subjects: Physics - Atomic Physics; Physics - Quantum Gases
• DOI: 10.48550/arxiv.1306.3365

Phys. Rev. A 89, 043417(2014) 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 $5\times 10^{19} m^{-3}$. 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.