Limits of sympathetic cooling of fermions: The role of the heat capacity of the coolant

Abstract

The sympathetic cooling of an initially degenerate Fermi gas by either an ideal Bose gas below $T_c$ or an ideal Boltzmann gas is investigated. It is shown that the efficiency of cooling by a Bose gas below $T_c$ is by no means reduced when its heat capacity becomes much less than that of the Fermi gas, where efficiency is measured by the decrease in the temperature of the Fermi gas per number of particles evaporated from the coolant. This contradicts the intuitive idea that an efficient coolant must have a large heat capacity. In contrast, for a Boltzmann gas a minimal value of the ratio of the heat capacities is indeed necessary to achieve T=0 and all of the particles must be evaporated.

arXiv comment5 pages, 3 figures

References in corpus (7)

• A quasi-pure Bose-Einstein condensate immersed in a Fermi sea
• Two-species mixture of quantum degenerate Bose and Fermi gases
• Fermi-Bose quantum degenerate ^40 K - ^87 Rb mixture with attractive interaction
• Fifty-fold improvement in the number of quantum degenerate fermionic atoms
• Reaching Fermi degeneracy in two-species optical dipole traps
• Cooling dynamics of ultracold two-species Fermi-Bose mixtures
• Three-Fluid Description of the Sympathetic Cooling of a Boson-Fermion Mixture

Cited by in corpus (6)

• Cooling and thermometry of atomic Fermi gases
• A Degenerate Bose-Fermi Mixture of Metastable Atoms
• Signatures of superfluidity for Feshbach-resonant Fermi gases
• Optimal cooling strategies for magnetically trapped atomic Fermi-Bose mixtures
• Thermodynamical approaches to efficient sympathetic cooling in ultracold Fermi-Bose atomic mixtures
• Production of a highly degenerate Fermi gas of metastable helium-3 atoms