Optical Feshbach resonances and ground state molecule production in the RbHg system

TL;DR

This paper explores the potential for creating ultracold RbHg molecules through optical Feshbach resonances and photoassociation, utilizing advanced ab initio calculations to assess feasibility and efficiency.

Contribution

It provides the first detailed theoretical analysis of optical Feshbach resonances and ground state molecule production in the Rb+Hg system using high-level ab initio methods.

Findings

Optical Feshbach resonances are strong at large laser detunings.

Ground state RbHg molecules can be produced with 20-50% efficiency.

Favorable Franck-Condon factors enable STIRAP transfer to the ground state.

Abstract

We present the prospects for photoassociation, optical control of interspecies scattering lengths and finally, the production of ultracold absolute ground state molecules in the Rb+Hg system. We use the "gold standard" ab initio methods for the calculations of ground (CCSD(T)) and excited state (EOM-CCSD) potential curves. The RbHg system, thanks to the wide range of stable Hg bosonic isotopes, offers possibilities for mass-tuning of ground state interactions. The optical lengths describing the strengths of optical Feshbach resonances near the Rb transitions are favorable even at large laser detunings. Ground state RbHg molecules can be produced with efficiencies ranging from about 20% for deeply bound to at least 50% for weakly bound states close to the dissociation limit. Finally, electronic transitions with favorable Franck-Condon factors can be found for the purposes of a STIRAP transfer of the weakly bound RbHg molecules to the absolute ground state using commercially available lasers.