Wave coarsening drives time crystallization in mechatronic metamaterials

量子物理学・ナノサイエンス第436回セミナー

概要

When metals are magnetized, emulsions phase separate, or galaxies cluster, domain walls and patterns form and irremediably coarsen over time. Such coarsening is universally driven by diffusive relaxation toward equilibrium. Here, we discover a vibrational counterpart---wave coarsening---in active elastic media: vibrations emerge and spontaneously grow in wavelength, period, and amplitude, before a globally synchronized state called a time crystal forms. We observe wave coarsening in one- and two-dimensional mechatronic metamaterials and capture its dynamical scaling. We further arrest the process by breaking momentum conservation and reveal a far-from-equilibrium nonlinear analogue to chiral topological edge modes. Our results open new questions about the transient physics of systems with non-potential interactions and suggest an organizing principle for nonlinear waves in acoustics, optomechanics, living matter, and soft robotics.