Classical Prethermal Phases of Matter

Systems subject to a high-frequency drive can spend an exponentially long time in a prethermal regime, in which novel phases of matter with no equilibrium counterpart can be realized. Because of the notorious computational challenges of quantum many-body systems, numerical investigations in this direction have remained limited to one spatial dimension, in which long-range interactions have been proven a necessity. Here, we show that prethermal nonequilibrium phases of matter are not restricted to the quantum domain. Studying the Hamiltonian dynamics of a large three-dimensional lattice of classical spins, we provide the first numerical proof of prethermal phases of matter in a system with short-range interactions. Concretely, we find higher-order as well as fractional discrete time crystals breaking the time-translational symmetry of the drive with unexpectedly large integer as well as fractional periods. Our work paves the way toward the exploration of novel prethermal phenomena by means of classical Hamiltonian dynamics with virtually no limitations on the system's geometry or size, and thus with direct implications for experiments.

Automated summary

Researchers have found that prethermal nonequilibrium phases of matter are not limited to quantum systems, and can also be observed in three-dimensional classical spin systems with short-range interactions. The discovery of higher-order and fractional discrete time crystals breaking time-translational symmetry opens up new possibilities for exploring novel prethermal phenomena using classical Hamiltonian dynamics, with implications for experiments.