Feshbach resonances in \(p\)-wave three-body recombination within Fermi-Fermi mixtures of open-shell \(^6\)Li and closed-shell \(^{173}\)Yb atoms

We report on observations and modeling of interspecies magnetic Feshbach resonances in dilute ultracold mixtures of open-shell alkali-metal \(^6\)Li and closed-shell \(^{173}\)Yb atoms with temperatures just above quantum degeneracy for both fermionic species. Resonances are located by detecting magnetic-field-dependent atom loss due to three-body recombination. We resolve closely-located resonances that originate from a weak separation-dependent hyperfine coupling between the electronic spin of \(^6\)Li and the nuclear spin of \(^{173}\)Yb, and confirm their magnetic field spacing by ab initio electronic-structure calculations. Through quantitative comparisons of theoretical atom-loss profiles and experimental data at various temperatures between 1 \(\mu\)K and 20 \(\mu\)K, we show that three-body recombination in fermionic mixtures has a \(p\)-wave Wigner threshold behavior leading to characteristic asymmetric loss profiles. Such resonances can be applied towards the formation of ultracold doublet ground-state molecules and quantum simulation of superfluid \(p\)-wave pairing.