Formation of fermionic molecules via interisotope Feshbach resonances

TL;DR

This paper improves lithium interaction models, analyzes Feshbach resonances in lithium isotopes, and predicts new resonances relevant for superfluidity research.

Contribution

It provides a refined description of lithium interactions, an analytic scattering model for Feshbach resonances, and predicts new resonances in mixed lithium isotopes.

Findings

Consistent description of $^6$Li interactions

Analytic model for the wide $^6$Li Feshbach resonance

Predicted new Feshbach resonances in $^6$Li-$^7$Li system

Abstract

We perform an analysis of recent experimental measurements and improve the lithium interaction potentials. For $^6$Li a consistent description can be given. We discuss theoretical uncertainties for the position of the wide $^6$Li Feshbach resonance, and we present an analytic scattering model for this resonance, based on the inclusion of a field-dependent virtual open-channel state. We predict new Feshbach resonances for the $^6$Li-$^7$Li system, and their importance for different types of crossover superfluidity models is discussed.