Two-Color Cooling Proposed for Fermions

Carlo Presilla and Roberto Onofrio of the Instituto Nazionale per la Fisica della Materia in Rome propose that the use of a bichromatic optical dipole trap will enable the realization of a deep Fermi degeneracy regime in a mixture of bosonic and fermionic atoms. They presented their most recent findings in the Jan. 24 issue of Physical Review Letters.

The scientists suggest that adding a coaxial blue-detuned laser to a boson-fermion mixture in an optical dipole trap would make the Fermi temperature higher than the Bose-Einstein critical temperature and would enable the noncondensed boson gas to cool the fermions. The sympathetic cooling technique promises to lead to a better understanding of phenomena in liquid helium and superconductors.