Atom-Dimer Scattering in a Three-Component Fermi Gas

TL;DR

This study investigates atom-dimer collisions in ultracold three-component Fermi gases, revealing resonant decay enhancements and suppression effects linked to Efimov states, which could enable control over molecular exchange reactions.

Contribution

It demonstrates experimental observation of Efimov-related phenomena in three-component Fermi gases, including decay resonances and suppression, advancing understanding of few-body physics in ultracold systems.

Findings

Resonant enhancement of decay due to Efimov-like trimer states crossing the continuum

Minima of decay indicating suppression of exchange reactions

Interference effects enabling control over reaction rates

Abstract

Ultracold gases of three distinguishable particles with large scattering lengths are expected to show rich few-body physics related to the Efimov effect. We have created three different mixtures of ultracold 6Li atoms and weakly bound 6Li2 dimers consisting of atoms in three different hyperfine states and studied their inelastic decay via atom-dimer collisions. We have found resonant enhancement of the decay due to the crossing of Efimov-like trimer states with the atom-dimer continuum in one mixture as well as minima of the decay in another mixture, which we interpret as a suppression of exchange reactions of the type |12>+|3> -> |23>+|1>. Such a suppression is caused by interference between different decay paths and demonstrates the possiblity to use Efimov physics to control the rate constants for molecular exchange reactions in the ultracold regime.