Two-photon photoassociation spectroscopy of an ultracold heteronuclear molecule

TL;DR

This paper demonstrates two-photon photoassociation spectroscopy of ultracold LiRb molecules, determining binding energies and discussing implications for molecule production via STIRAP.

Contribution

It provides new measurements of binding energies of LiRb molecules and analyzes the potential for ground state molecule creation using two-photon processes.

Findings

Strong two-photon PA lines observed at low laser intensity

Binding energies of ground singlet and triplet states determined

Implications for STIRAP-based molecule formation discussed

Abstract

We report on two-photon photoassociation (PA) spectroscopy of ultracold heteronuclear LiRb molecules. This is used to determine the binding energies of the loosely bound levels of the electronic ground singlet and the lowest triplet states of LiRb. We observe strong two-photon PA lines with power broadened line widths greater than 20 GHz at relatively low laser intensity of 30 W/cm$^{2}$. The implication of this observation on direct atom to molecule conversion using stimulated Raman adiabatic passage (STIRAP) is discussed and the prospect for electronic ground state molecule production is theoretically analyzed.