Dissipative time crystal in a strongly interacting Rydberg gas

TL;DR

This paper reports the experimental observation of a dissipative time crystal in a room-temperature Rydberg gas, demonstrating persistent oscillations and long-range temporal order due to the interplay of Rydberg states and dissipation.

Contribution

First experimental realization of a dissipative time crystal in a room-temperature atomic gas, showing persistent oscillations and robustness against noise.

Findings

Persistent oscillations of photon transmission indicate time crystalline order.

Time crystal arises from coexistence and competition of Rydberg states.

Long-range temporal order confirmed by autocorrelation and noise robustness.

Abstract

The notion of spontaneous symmetry breaking has been well established to characterize classical and quantum phase transitions of matter, such as in condensation, crystallization or quantum magnetism. Generalizations of this paradigm to the time dimension can lead to a time crystal phase, which spontaneously breaks the time translation symmetry of the system. Whereas the existence of a continuous time crystal at equilibrium has been challenged by no-go theorems, this difficulty can be circumvented by dissipation in an open system. Here, we report the experimental observation of such dissipative time crystalline order in a room-temperature atomic gas, where ground-state atoms are continuously driven to Rydberg states. The emergent time crystal is revealed by persistent oscillations of the photon transmission, and we show that the observed limit cycles arise from the coexistence and competition between distinct Rydberg components. The nondecaying autocorrelation of the oscillation, together with the robustness against temporal noises, indicate the establishment of true long-range temporal order and demonstrates the realization of a continuous time crystal.