Hengyun (Harry) Zhou (Harvard University)

Discrete Time Crystals in Black Diamond

The interplay of periodic driving, disorder, and strong interactions has recently been predicted to result in exotic "time-crystalline" phases, which spontaneously break the discrete time-translation symmetry of the underlying drive. Here, we report the experimental observation of such discrete time-crystalline order in a driven, disordered ensemble of ~10^6 dipolar spin impurities in diamond at room-temperature. We observe long-lived temporal correlations at integer multiples of the fundamental driving period, experimentally identify the phase boundary and find that the temporal order is protected by strong interactions. We also discuss how such order can be utilized as a probe of thermalization, as well as how new pulse sequences can engineer interactions and potentially enable sensitive magnetometry with these spin ensembles.