Three-body recombination in a three-state Fermi gas with widely tunable interactions

TL;DR

This study explores the stability and three-body recombination processes in a three-state ultracold fermionic gas of $^6$Li across various magnetic fields, revealing conditions for high stability and resonant loss features.

Contribution

It provides the first detailed measurement of three-body loss coefficients in a three-state Fermi gas over a wide magnetic field range, highlighting stability conditions and resonant loss phenomena.

Findings

Three-body loss coefficient varies over four orders of magnitude.

High stability when two scattering lengths are small.

Resonant loss features near Feshbach resonances.

Abstract

We investigate the stability of a three spin state mixture of ultracold fermionic $^6$Li atoms over a range of magnetic fields encompassing three Feshbach resonances. For most field values, we attribute decay of the atomic population to three-body processes involving one atom from each spin state and find that the three-body loss coefficient varies by over four orders of magnitude. We observe high stability when at least two of the three scattering lengths are small, rapid loss near the Feshbach resonances, and two unexpected resonant loss features. At our highest fields, where all pairwise scattering lengths are approaching $a_t = -2140 a_0$, we measure a three-body loss coefficient $L_3 \simeq 5\times 10^{-22} \mathrm{cm}^6/\mathrm{s}$ and a trend toward lower decay rates for higher fields indicating that future studies of color superfluidity and trion formation in a SU(3) symmetric Fermi gas may be feasible.