Atom-dimer scattering and long-lived trimers in fermionic mixtures

TL;DR

This paper investigates atom-dimer scattering in heteronuclear fermionic mixtures near a Feshbach resonance, revealing tunable p-wave resonances and long-lived trimers that are promising for many-body physics studies.

Contribution

It introduces a mechanism to control p-wave interactions via confinement in heteronuclear mixtures, enabling the formation of stable, long-lived trimers.

Findings

Discovery of a tunable p-wave atom-dimer resonance.

Identification of long-lived, weakly bound trimers.

Implications for experiments with Lithium-Potassium mixtures.

Abstract

We consider a heteronuclear fermionic mixture on the molecular side of an interspecies Feshbach resonance and discuss atom-dimer scattering properties in uniform space and in the presence of an external confining potential, restricting the system to a quasi-2D geometry. We find that there is a peculiar atom-dimer p-wave resonance which can be tuned by changing the frequency of the confinement. Our results have implications for the ongoing experiments on Lithium-Potassium mixtures, where this mechanism allows for switching the p-wave interaction between a K atom and Li-K dimer from attractive to repulsive, and forming a weakly bound trimer with unit angular momentum. We show that such trimers are long-lived and the atom-dimer resonance does not enhance inelastic relaxation in the mixture, making it an outstanding candidate for studies of p-wave resonance effects in a many-body system.