Extreme Loss Suppression and Wide Tunability of Dipolar Interactions in an Ultracold Molecular Gas

Abstract: Ultracold dipolar molecules hold great promise for the creation of novel quantum states of matter, but the realization of long-lived molecular bulk samples with strong dipole-dipole interactions has remained elusive. Here, we realize a collisionally stable gas of ultracold ground state molecules with a lifetime of several seconds. Utilizing double microwave dressing, we achieve an extreme suppression of inelastic two- and three-body losses by factors of more than 10,000 and 1,000, respectively. We find that losses remain suppressed across a wide range of dipole-dipole interactions, allowing the continuous tuning of the dipolar length from 0 to 1 um $\sim$ 20,000 $a_0$. Combined with the recent realization of Bose-Einstein condensation of dipolar molecules, our findings open the door to the exploration of strongly dipolar quantum liquids.