Cooperative excitation and many-body interactions in a cold Rydberg gas

TL;DR

This paper investigates the dynamics and counting statistics of Rydberg excitations in ultra-cold Rubidium atoms, demonstrating the effects of dipole blockade and interactions through experimental results and a novel theoretical model.

Contribution

It introduces a new theoretical model based on Dicke states that accurately describes Rydberg interactions and counting statistics in cold atom experiments.

Findings

Observation of sub-Poissonian counting statistics on resonance.

Observation of super-Poissonian counting statistics off resonance.

Good agreement between experimental data and the new theoretical model.

Abstract

The dipole blockade of Rydberg excitations is a hallmark of the strong interactions between atoms in these high-lying quantum states. One of the consequences of the dipole blockade is the suppression of fluctuations in the counting statistics of Rydberg excitations, of which some evidence has been found in previous experiments. Here we present experimental results on the dynamics and the counting statistics of Rydberg excitations of ultra-cold Rubidium atoms both on and off resonance, which exhibit sub- and super-Poissonian counting statistics, respectively. We compare our results with numerical simulations using a novel theoretical model based on Dicke states of Rydberg atoms including dipole-dipole interactions, finding good agreement between experiment and theory.