Quantum-classical model for the formation of Rydberg molecules

A fascinating aspect of Rydberg atoms is their ability to form huge but very weakly bound molecules with a ground-state atom, only held together by a scattering process between the latter and the Rydberg electron. Beyond the usual way of creating such molecules by laser excitation from two ground-state atoms with a distance of less than the Rydberg radius, we demonstrate that Rydberg molecules can also be formed by capturing a ground-state atom which is initially located outside the range of the Rydberg atom when it comes in contact with it. To demonstrate this effect, we investigate the scattering process between the Rydberg electron and the ground-state atom within a quantum-classical framework. In this picture, the capture results from a dissipative finite-mass correction term in the classical equations of motion. We show that, and under which conditions the capturing takes place.