Cooling and thermometry of atomic Fermi gases

TL;DR

This paper reviews advanced cooling and thermometry techniques for atomic Fermi gases, emphasizing methods to reach deep quantum degeneracy and their applications in studying quantum phases.

Contribution

It provides a comprehensive overview of cooling strategies, experimental progress, and extensions to optical lattices for Fermi gases, highlighting new proposals and implementations.

Findings

Sympathetic cooling effectively achieves deep Fermi degeneracy.

Extensions to optical lattices enable exploration of quantum phase transitions.

Precision thermometry is crucial for understanding Fermi gas phase diagrams.

Abstract

We review the status of cooling techniques aimed at achieving the deepest quantum degeneracy for atomic Fermi gases. We first discuss some physical motivations, providing a quantitative assessment of the need for deep quantum degeneracy in relevant physics cases, such as the search for unconventional superfluid states. Attention is then focused on the most widespread technique to reach deep quantum degeneracy for Fermi systems, sympathetic cooling of Bose-Fermi mixtures, organizing the discussion according to the specific species involved. Various proposals to circumvent some of the limitations on achieving the deepest Fermi degeneracy, and their experimental realizations, are then reviewed. Finally, we discuss the extension of these techniques to optical lattices and the implementation of precision thermometry crucial to the understanding of the phase diagram of classical and quantum phase transitions in Fermi gases.