Observation of discrete time-crystalline order in a disordered dipolar many-body system

Abstract

Understanding quantum dynamics away from equilibrium is an outstanding challenge in the modern physical sciences. It is well known that out-of equilibrium systems can display a rich array of phenomena, ranging from self organized synchronization to dynamical phase transitions1,2. More recently, advances in the controlled manipulation of isolated many-body systems have enabled detailed studies of non-equilibrium phases in strongly interacting quantum matter3–6. As a particularly striking example, the interplay of periodic driving, disorder, and strong interactions has recently been predicted to result in exotic “time-crystalline” phases7, which spontaneously break the discrete timetranslation symmetry of the underlying drive8–11. Here, we report the experimental observation of such discrete time-crystalline order in a driven, disordered ensemble of ∼ 106 dipolar spin impurities in diamond at room-temperature12–14. 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; this order is remarkably stable against perturbations, even in the presence of slow thermalization15, 16. Our work opens the door to exploring dynamical phases of matter and controlling interacting, disordered many-body systems17-19.