Progress on direct photoassociation of halo molecules in ultracold $^{86}$Sr

We report progress on the creation of $^1S_0$+$^1S_0$ halo molecules in strontium 86 through direct photoassociation in an optical dipole trap. By driving a two photon Raman transition near-resonance with a molecular level of the $^1S_0$+$^3P_1$ interatomic potential, we explore a unique regime of photoassociation where the driving fields are separeted by small energy differences. A simple isolated resonance model confirms the binding energy, $E_b \approx 84$ kHz at low excitation-laser intensity. Additionally, we have investigated the effects of density shifts and trap intensity on the observed halo binding energy. Large observed Frank-Condon factors suggest that STIRAP should be very effective for improving molecular conversion efficiency. Further experiments in a 3D lattice will explore molecular lifetimes and collision rates.