A High Phase-Space-Density Gas of Polar Molecules

Understand

A quantum gas of ultracold polar molecules, with long-range and anisotropic interactions, would not only enable explorations of a large class of many-body physics phenomena, but could also be used for quantum information processing.

• We report on the creation of an ultracold dense gas of 40K87Rb polar molecules.
• Using a single step of STIRAP (STImulated Raman Adiabatic Passage) via two-frequency laser irradiation, we coherently transfer extremely weakly bound KRb molecules to the rovibrational ground state of either the triplet or the singlet electronic ground molecular potential.
• The polar molecular gas has a peak density of 10^12 cm^-3, and an expansion-determined translational temperature of 350 nK.