Spatial correlations of Rydberg excitations in optically driven atomic ensembles

TL;DR

This paper investigates the spatial correlations of Rydberg excitations in driven atomic ensembles, revealing quasi-crystalline patterns and the effects of long-range interactions through numerical and analytical methods.

Contribution

It introduces a detailed analysis of many-body correlations in Rydberg systems using exact numerical solutions and Monte Carlo simulations, highlighting the emergence of quasi-crystalline order.

Findings

Superatom excitation probability saturates at 1/2 for coherent driving.

Incoherent driving increases excitation probability towards unity with more atoms.

Rydberg excitations form damped oscillatory correlations indicative of quasi-crystallization.

Abstract

We study the emergence of many-body correlations in the stationary state of continuously-driven, strongly-interacting dissipative system. Specifically, we examine resonant optical excitations of Rydberg states of atoms interacting via long-range dipole-dipole and van der Waals potentials employing exact numerical solutions of the density matrix equations and Monte-Carlo simulations. Collection of atoms within a blockade distance form a "superatom" that can accommodate at most one Rydberg excitation. The superatom excitation probability saturates to 1/2 for coherently driven atoms, but is significantly higher for incoherent driving, approaching unity as the number of atoms increases. In the steady state of uniformly-driven, extended one-dimensional system, the saturation of superatoms leads to quasi-crystallization of Rydberg excitations whose correlations exhibit damped spatial oscillations. The behavior of the system under the van der Waals interaction potential can be approximated by an analytically soluble model based on a "hard-rod" interatomic potential.