Three-body recombination near a narrow Feshbach resonance in $^6$Li

TL;DR

This study experimentally and theoretically investigates three-body recombination in ultracold $^6$Li near a narrow Feshbach resonance, revealing universal behavior governed by long-range interactions across a wide temperature range.

Contribution

It provides a comprehensive analysis of three-body recombination near a narrow Feshbach resonance, demonstrating universal behavior and a set of rate equations applicable over broad conditions.

Findings

Recombination rate $L_3$ depends on magnetic field and temperature.

Recombination follows a universal pattern dictated by van der Waals potential.

The physical model applies to various resonances and temperature regimes.

Abstract

We experimentally measure, and theoretically analyze the three-atom recombination rate, $L_3$, around a narrow $s$ wave magnetic Feshbach resonance of $^6$Li-$^6$Li at 543.3 Gauss. By examining both the magnetic field dependence and especially the temperature dependence of $L_3$ over a wide range of temperatures from a few $\mu$K to above 200 $\mu$K, we show that three-atom recombination through a narrow resonance follows a universal behavior determined by the long-range van der Waals potential, and can be described by a set of rate equations in which three-body recombination proceeds via successive pairwise interactions. We expect the underlying physical picture to be applicable not only to narrow $s$ wave resonances, but also to resonances in nonzero partial waves, and not only at ultracold temperatures, but also at much higher temperatures.