arXiv:1802.00457 · Physical review. B./Physical review. B
P31 NMR study of discrete time-crystalline signatures in an ordered crystal of ammonium dihydrogen phosphate
Jared Rovny, Robert L. Blum, Sean Barrett
Abstract
Periodic driving of an interacting spin system may lead to unusual out-of-equilibrium states of matter, such as the discrete time crystal (DTC). Two recent experiments have reported a key signature of the DTC: for long enough interaction times, the system's response becomes rigidly locked to one half of the driving frequency. Using nuclear magnetic resonance, the authors observe this DTC signature in the most unexpected system to date: a three-dimensional, spatially ordered crystal. This challenges the paradigm that the DTC arises from many-body localization. Furthermore, hidden coherence in the system is revealed by the ``DTC echo'' experiment, and the effect of interactions during drive pulses is demonstrated.