Laser Spectroscopy of Bound NaNe Molecules

We have produced the van der Waals molecule NaNe in a supersonic expansion, and have studied the $A{}_{}{}^2{}_{}{}^{}\Pi \to X{}_{}{}^2{}_{}{}^{}\Sigma$ transition using a single-mode cw dye laser. Using analysis based on isotope shifts and the long-range $R^{-6\mathrm{}}$ behavior of the excited-state $A{}_{}{}^2{}_{}{}^{}\Pi$ potential, we find its well depth and location to be $D_{\mathrm{eA}}=140\mathrm{}\pm 3$ ${\mathrm{cm}}^{-1\mathrm{}}$ at ${\mathcal{r}}_{\mathrm{eA}}=(5.1\mathrm{}\pm 0.1)a_0$ and for the $X{}_{}{}^2{}_{}{}^{}\Sigma$ ground state, $D_{\mathrm{eX}}=8.1\mathrm{}\pm 0.9$ ${\mathrm{cm}}^{-1\mathrm{}}$ at ${\mathcal{r}}_{\mathrm{eX}}=(10.0\mathrm{}\pm 0.2)a_0$. These results are compared with pseudopotential calculations and several recent line-broadening and collisions experiments.