Observation of Anomalous Decay of a Polarized Three-Component Fermi Gas

Abstract: Systems of fermions with multiple internal states, such as quarks in quantum chromodynamics and nucleons in nuclear matter, are at the heart of some of the most complex quantum many-body problems. The stability of such many-body multi-component systems is crucial to understanding, for instance, baryon formation and the structure of nuclei, but these fermionic problems are typically very challenging to tackle theoretically. Versatile experimental platforms on which to study analogous problems are thus sought after. Here, we report the creation of a uniform gas of three-component fermions. We characterize the decay of this system across a range of interaction strengths and observe nontrivial competition between two- and three-body loss processes. We observe anomalous decay of the polarized (i.e. spin-population imbalanced) gas, in which the loss rates of each component unexpectedly differ. We introduce a generalized three-body rate equation which captures the decay dynamics, but the underlying microscopic mechanism is unknown.