Using fitted model potential curves of the ground and lowest three excited states yielded by the relativistic Kramers-restricted multireference configuration interaction method with 19 electrons correlated, we theoretically investigate the rovibrational properties including the number of vibrational state and diagonally distributed Franck-Condon factors for a ${}^{87}\text{Rb}{}^{84}\text{Sr}$ molecule. Benefiting from a turning point at about $v^{\prime }=20$ for the Franck-Condon factors between the ground state and spin-orbit $2(\Omega =1/2)$ excited state, we choose $|2(\Omega =1/2),v^{\prime }=21,J^{\prime }=1\rangle$ as the intermediate state in the three-level model to theoretically analyze the possibility of performing stimulated Raman adiabatic passage to transfer weakly bound RbSr molecules to the rovibrational ground state. With 1550 nm pump laser (2 W/${\text{cm}}^2$) and 1342 nm dump laser (10 mW/${\text{cm}}^2$) employed and appropriate settings of pulse time length (about 300 $\mu$s), we have formalistically achieved a round-trip transfer efficiency of 60%, namely 77% for one-way transfer. The results demonstrate the possibility of producing polar ${}^{87}\text{Rb}{}^{84}\text{Sr}$ molecules efficiently in a submicrokelvin regime, and further provide promising directions for future theoretical and experimental studies on alkali-alkaline(rare)-earth dimers.

• Received 4 April 2014

DOI:https://doi.org/10.1103/PhysRevA.89.063402