Molecular production at a wide Feshbach resonance in Fermi-gas of cooled atoms

TL;DR

This paper models molecular production in a fermionic gas near a wide Feshbach resonance, revealing high sensitivity to initial conditions and broad momentum distribution of the resulting BCS condensate.

Contribution

It reduces the molecular production problem to a Landau-Zener model and highlights the effects of strong interactions and initial magnetic field on outcomes.

Findings

Molecular production is highly sensitive to initial magnetic field values.

A large BCS condensate with broad momentum distribution is generated.

Strong interactions significantly renormalize the energy gap.

Abstract

The problem of molecular production from degenerate gas of fermions at a wide Feshbach resonance, in a single-mode approximation, is reduced to the linear Landau-Zener problem for operators. The strong interaction leads to significant renormalization of the gap between adiabatic levels. In contrast to static problem the close vicinity of exact resonance does not play substantial role. Two main physical results of our theory is the high sensitivity of molecular production to the initial value of magnetic field and generation of a large BCS condensate distributed over a broad range of momenta in inverse process of the molecule dissociation.