Formation of silver dimers by one-photon photo- and magneto-association of ultracold Ag atoms

We have performed three theoretical simulations relevant for the formation of Ag₂ molecules from laser cooled silver atoms. Firstly, we determined the relativistic electronic structure of Ag₂ molecules in ground and low-lying excited states. Secondly, we computed rotational and vibrational levels of the ground and excited electronic states as well as rovibrationally averaged electric transition dipole moments. Using this knowledge, we analyzed a simplified model of the one-photon photo-association process to form electronically excited Ag₂ from microkelvin Ag atoms. Finally and thirdly, we performed quantum-mechanical coupled-channels calculations, numerical solutions of sets of coupled radial Schrodinger equations of ground-state Ag collisions in an external magnetic field. These collisions occur in a non-zero magnetic field and include the effects of hyperfine Fermi-contact and Zeeman interactions. We predict s-wave scattering lengths as well as strengths and distribution of Fano-Feshbach resonances as a function of the magnetic field strength. The Fano-Feshbach resonances can be used to magneto-associate ultracold Ag atoms into weakly bound ground-state Ag₂ dimers.