Antiferromagnetic phase transition in a nonequilibrium lattice of Rydberg atoms

TL;DR

This paper investigates the phase transitions in a driven-dissipative Rydberg atom lattice, revealing continuous and oscillatory phases, as well as bistability, using mean-field theory.

Contribution

It introduces a mean-field analysis of nonequilibrium Rydberg systems, uncovering new phase behaviors including oscillations and bistability.

Findings

Identified a continuous transition between uniform and antiferromagnetic phases.

Discovered a novel oscillatory phase in the nonequilibrium system.

Observed bistability between different phases depending on laser parameters.

Abstract

We study a driven-dissipative system of atoms in the presence of laser excitation to a Rydberg state and spontaneous emission. The atoms interact via the blockade effect, whereby an atom in the Rydberg state shifts the Rydberg level of neighboring atoms. We use mean-field theory to study how the Rydberg population varies in space. As the laser frequency changes, there is a continuous transition between the uniform and antiferromagnetic phases. The nonequilibrium nature also leads to a novel oscillatory phase and bistability between the uniform and antiferromagnetic phases.