Ultracold dense samples of dipolar RbCs molecules in the rovibrational and hyperfine ground state

TL;DR

This paper demonstrates the creation of ultracold dense samples of RbCs molecules in their ground state with high efficiency, revealing their dipolar nature and potential for stable quantum gases.

Contribution

It reports a new method for producing ultracold RbCs molecules in their ground state with high efficiency and full hyperfine control, highlighting their dipolar properties.

Findings

Achieved 90% efficiency in molecule transfer via STIRAP.

Observed hyperfine-changing collisions at certain magnetic fields.

Detected quadratic shifts indicating strong dipolar interactions.

Abstract

We produce ultracold dense trapped samples of 87Rb133Cs molecules in their rovibrational ground state, with full nuclear hyperfine state control, by stimulated Raman adiabatic passage (STIRAP) with efficiencies of 90%. We observe the onset of hyperfine-changing collisions when the magnetic field is ramped so that the molecules are no longer in the hyperfine ground state. A strong quadratic shift of the transition frequencies as a function of applied electric field shows the strongly dipolar character of the RbCs ground-state molecule. Our results open up the prospect of realizing stable bosonic dipolar quantum gases with ultracold molecules.