Molecular regimes in ultracold Fermi gases

TL;DR

This paper reviews how Feshbach resonances enable control of interactions in ultracold Fermi gases, leading to the creation of large, stable diatomic molecules that exhibit unique quantum statistical properties.

Contribution

It introduces theoretical approaches and discusses the physics of molecular regimes in Fermi gases, emphasizing quantum statistical effects and the formation of novel composite bosons.

Findings

Creation of large, stable diatomic molecules of fermionic atoms.

Observation of molecules exhibiting features of Fermi statistics.

Analysis of quantum statistical effects in molecular regimes.

Abstract

The use of Feshbach resonances for tuning the interparticle interaction in ultracold Fermi gases has led to remarkable developments, in particular to the creation and Bose-Einstein condensation of weakly bound diatomic molecules of fermionic atoms. These are the largest diatomic molecules obtained so far, with a size of the order of thousands of angstroms. They represent novel composite bosons, which exhibit features of Fermi statistics at short intermolecular distances. Being highly excited, these molecules are remarkably stable with respect to collisional relaxation, which is a consequence of the Pauli exclusion principle for identical fermionic atoms. The purpose of this review is to introduce theoretical approaches and describe the physics of molecular regimes in two-component Fermi gases and Fermi-Fermi mixtures, focusing attention on quantum statistical effects.