Non-adiabatic motional effects and dissipative blockade for Rydberg atoms excited from optical lattices or microtraps

TL;DR

This paper demonstrates that motional effects and mechanical forces among Rydberg atoms in optical lattices or microtraps can cause decoherence and dissipative blockade, challenging common approximations in Rydberg excitation modeling.

Contribution

It reveals how atomic motion and forces influence Rydberg excitation dynamics, highlighting the breakdown of frozen gas and Born-Oppenheimer approximations in these systems.

Findings

Motional effects cause decoherence in Rydberg excitation.

Mechanical forces induce a dissipative blockade effect.

Motional effects impact Rydberg dressing regimes.

Abstract

The laser-excitation of Rydberg atoms in ultracold gases is often described assuming that the atomic motion is frozen during the excitation time. We show that this frozen gas approximation can break down for atoms that are held in optical lattices or microtraps. In particular, we show that the excitation dynamics is in general strongly affected by mechanical forces among the Rydberg atoms as well as the spread of the atomic wavepacket in the confining potential. This causes decoherence in the excitation dynamics - resulting in a dissipative blockade effect - that renders the Rydberg excitation inefficient even in the anti-blockade regime. For a strongly off-resonant laser excitation - usually considered in the context of Rydberg dressing - these motional effects compromise the applicability of the Born-Oppenheimer approximation. In particular, our results indicate that they can lead to decoherence also in the dressing regime.