Frequency Comb Behavior of Time Crystals in an RF-Driven Dissipative Rydberg System

TL;DR

This study demonstrates how a driven-dissipative Rydberg atomic system can exhibit time crystal behavior with tunable oscillation frequencies, leading to frequency comb formation and nonlinear synchronization.

Contribution

It introduces a new platform using interacting Rydberg atoms to explore nonequilibrium time crystals, frequency combs, and nonlinear dynamics, supported by experimental and theoretical analysis.

Findings

Observation of a driven-dissipative time crystal in Rydberg vapor

Tunable intrinsic oscillation frequency via RF field

Emergence of a frequency comb in atomic coherence

Abstract

Driven nonlinear oscillators constitute a universal paradigm for understanding synchronization, frequency pulling, and frequency comb formation in nonequilibrium systems. Here, we realize such an emergent nonlinear oscillator in strongly interacting cesium Rydberg vapor, where coherent optical excitation, dissipation, and long-range interactions give rise to a driven-dissipative time crystal phase with intrinsic oscillation frequencies. Applying a radio-frequency (RF) field allows controlled tuning of the intrinsic oscillation frequency. Under RF heterodyne conditions, we observe intermodulation, frequency pulling, and, at strong drive, the emergence of a comb-like spectrum in the atomic coherence. We quantitatively capture these observations using a four-level mean-field model and demonstrate a classical analogue with a driven Van der Pol oscillator. Our results establish interacting Rydberg ensembles as a tunable platform for exploring nonequilibrium time-crystalline order, nonlinear synchronization, and frequency comb generation in many-body atomic systems.