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

TL;DR

This paper investigates magnetic Feshbach resonances in ultracold mixtures of $^6$Li and $^{173}$Yb atoms, revealing $p$-wave behavior in three-body recombination and potential applications in molecule formation and quantum simulation.

Contribution

It reports the first observation and modeling of $p$-wave Feshbach resonances in $^6$Li-$^{173}$Yb mixtures, including resolving closely-located resonances and confirming their properties with ab initio calculations.

Findings

Detection of magnetic-field-dependent atom loss indicating Feshbach resonances.

Identification of $p$-wave threshold behavior in three-body recombination.

Confirmation of resonance properties through theoretical calculations.

Abstract

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.