Abstract
We present spectra of ultracold molecules in their electronic ground state formed by spontaneous decay of weakly bound photoassociated molecules. Beginning with atoms in a dual-species magneto-optical trap, weakly bound molecules are formed in the 4(1) electronic state, which corresponds to the state at short range. These molecules spontaneously decay to the electronic ground state and we use resonantly enhanced multiphoton ionization to determine the vibrational population distribution in the electronic ground states after spontaneous emission. Many of the observed lines from the spectra are consistent with transitions from the ground electronic state to either the or the electronic state that has been previously observed, with levels possibly as low as being populated. We do not observe decay to weakly bound vibrational levels of the or electronic state in the spectra. We also deduce a lower bound of for the dissociation energy of the molecular ion.
- Received 20 October 2014
DOI:https://doi.org/10.1103/PhysRevA.90.062513
©2014 American Physical Society