Resonant Rydberg-Atom-Rydberg-Atom Collisions

This is the authors' abstract. We don't add key points for this paper.

We have observed the sharply resonant enhancement of the cross section of the collision process ns+ns→np+(n-1)p between two Nans ($16<~n<~27$) atoms which occurs when the levels are shifted by an electric field so that the $ns$ level lies midway between the two p states. The widths of the collisional resonances scale as n^-2 and the magnitudes of the cross sections as n⁴, with values of 0.5 GHz and 8×{}10⁸ ² for the $20s$ state. These results are in good agreement with calculations based on the long-range dipole-dipole interaction between the two atoms.