Non-adiabatic dynamics in Rydberg gases with random atom positions

TL;DR

This paper investigates non-adiabatic transitions in Rydberg gases with random atom positions, showing how these effects can be experimentally observed through ionization measurements.

Contribution

It demonstrates that non-adiabatic transitions are common in Rydberg gases with random configurations and proposes an excitation scheme to observe these effects experimentally.

Findings

Non-adiabatic transitions are prevalent in randomly excited Rydberg gases.

Almost all Rydberg ionization can be linked to non-adiabatic transitions.

A microwave resonance scheme enables selective excitation of specific states.

Abstract

Assemblies of highly excited Rydberg atoms in an ultracold gas can be set into motion by a combination of van-der-Waals and resonant dipole-dipole interactions. Thereby, the collective electronic Rydberg state might change due to non-adiabatic transitions, in particular if the configuration encounters a conical interaction. For the experimentally most accessible scenario, in which the Rydberg atoms are initially randomly excited in a three-dimensional bulk gas under blockade conditions, we numerically show that non-adiabatic transitions can be common when starting from the most energetic repulsive BO-surface. We outline how this state can be selectively excited using a microwave resonance, and demonstrate a regime where almost all collisional ionization of Rydberg atoms can be traced back to a prior non-adiabatic transition. Since Rydberg ionisation is relatively straightforward to detect, the excitation and measurement scheme considered here renders non-adiabatic effects in Rydberg motion easier to demonstrate experimentally than in scenarios considered previously.