Observation of a time crystal comb in a driven-dissipative system with Rydberg gas

Time crystals, as temporal analogs of space crystals, manifest as stable and periodic behavior that breaks time translation symmetry. In an open quantum system, many-body interaction subjected to dissipation allows one to develop the time crystalline order in an unprecedented way, as refer to dissipative time crystal. Here we report the observation of a time crystal comb in the continuously driven-dissipative and strongly interacting Rydberg thermal gas, in which continuous time crystal and sub-harmonics of limit cycles as well as the high-order harmonic oscillation phases are observed in the same system by manipulating the Rydberg excitation. Our work provides new ways to explore the nonequilibrium phases of matter in open systems. Such time crystals with persistent oscillation rooted in emergent quantum correlations, may emerge as a ubiquitous tool in quantum metrology, for instance, continuous sensing and parameter estimation surpassing the standard quantum limit.