Long-Lived Ultracold Molecules with Electric and Magnetic Dipole Moments

TL;DR

This paper reports the creation of long-lived ultracold fermionic NaLi molecules with electric and magnetic dipole moments, achieved through magneto-association and STIRAP, with a lifetime nearing the p-wave universal limit.

Contribution

It demonstrates the production of long-lived ultracold NaLi molecules in their triplet ground state with detailed hyperfine structure characterization, a significant step for dipolar quantum gases.

Findings

Produced 3×10^4 ground state molecules

Observed a 4.6 s lifetime approaching the p-wave limit

Determined hyperfine structure via ESR spectroscopy

Abstract

We create fermionic dipolar $^{23}$Na$^6$Li molecules in their triplet ground state from an ultracold mixture of $^{23}$Na and $^6$Li. Using magneto-association across a narrow Feshbach resonance followed by a two-photon STIRAP transfer to the triplet ground state, we produce $3\,{\times}\,10^4$ ground state molecules in a spin-polarized state. We observe a lifetime of $4.6\,\text{s}$ in an isolated molecular sample, approaching the $p$-wave universal rate limit. Electron spin resonance spectroscopy of the triplet state was used to determine the hyperfine structure of this previously unobserved molecular state.