Evidence for Ground- and Excited-State Efimov Trimers in a Three-State Fermi Gas
Abstract
We observe enhanced three-body recombination in an ultracold three-component 6Li Fermi gas with large but unequal scattering lengths attributable to an excited Efimov trimer state near the three-atom scattering threshold. We find excellent agreement between the measured three-body recombination rate and the recombination rate calculated in the zero-range approximation where the only free parameters are the Efimov parameters * and η*. The value of * determined by the location of the Efimov resonance we observe at 895 G also predicts the locations of loss features previously observed near 130 and 500 G Jochim08,OHara09 suggesting that all three features are associated with universal Efimov trimer states. We also report on the first realization of a quantum degenerate three-state Fermi gas with approximate SU(3) symmetry.