Phase Diagram of Rydberg atoms in a nonequilibrium optical lattice

TL;DR

This paper explores the complex nonequilibrium quantum phases of Rydberg atoms in an optical lattice, demonstrating how phase control is achieved via light intensity ratios and detuning, with implications for studying Rydberg blockade phenomena.

Contribution

It provides the first detailed phase diagram of Rydberg atoms in a nonequilibrium optical lattice considering spontaneous emission effects.

Findings

Identification of uniform, antiferromagnetic, and oscillatory phases.

Control of phases through light intensity ratios and detuning.

Existence of bistability under certain parameter conditions.

Abstract

We study the quantum nonequilibrium dynamics of ultracold three-level atoms trapped in an optical lattice, which are excited to their Rydberg states via a two-photon excitation with nonnegligible spontaneous emission. Rich quantum phases including uniform phase, antiferromagnetic phase and oscillatory phase are identified. We map out the phase diagram and find these phases can be controlled by adjusting the ratio of intensity of the pump light to the control light, and that of two-photon detuning to the Rydberg interaction strength. When the two-photon detuning is blue-shifted and the latter ratio is less than 1, bistability exists among the phases. Actually, this ratio controls the Rydberg-blockade and antiblockade effect, thus the phase transition in this system can be considered as a possible approach to study both effects.