Diffusive-like Redistribution in State-changing Collisions between Rydberg Atoms and Ground State Atoms

TL;DR

This study investigates state-changing collisions between Rydberg and ground state atoms, revealing a broad redistribution of populations across multiple states due to a charge exchange process, modeled as a diffusive-like behavior within a Rydberg quasi-molecular complex.

Contribution

It demonstrates that collisions lead to a wide range of final states, not limited to a single manifold, and introduces a model explaining this diffusive-like redistribution.

Findings

Population redistributes over many final states.

Decay to states with same l but different n occurs.

Final state distribution exhibits diffusive-like behavior.

Abstract

We report on the study of state-changing collisions between Rydberg atoms and ground state atoms. We employ high-resolution momentum spectroscopy to identify the final states. In contrast to previous studies, we find that the outcome of such collisions is not limited to a single hydrogenic manifold. We observe a redistribution of population over a wide range of final states. We also find that even the decay to states with the same $l$ as the initial state, but different principal quantum number $n$ is possible. We model the underlying physical process in the framework of a short-lived Rydberg quasi-molecular complex, where a charge exchange process gives rise to an oscillating electric field that causes transitions within the Rydberg manifold. The distribution of final states shows a diffusive-like behavior.