Rubidium Rydberg macrodimers

We explore long-range interactions between two atoms excited into high principal quantum number n Rydberg states, and present calculated potential energy curves for various symmetries of doubly excited ns and np rubidium atoms. We show that the potential curves for these symmetries exhibit deep (similar to GHz) potential wells, which can support very extended (similar to mu m) bound vibrational states (macrodimers). We present n-scaling relations for both the depth D-e of the wells and the equilibrium separations R-e of these macrodimers, and explore their response to small electric fields and stability with respect to predissociation. Finally, we present a scheme to form and study these macrodimers via photoassociation, and show how one can probe the various l-character of the potential wells.