Anomalous coarsening in charge density wave states in one-dimensional Holstein model under quantum quench

We investigate the coarsening dynamics of charge-density-wave (CDW) states in the one-dimensional semiclassical Holstein model following a quantum quench. When a weak electron–lattice coupling is suddenly switched on, the system remains disordered; however, at stronger post-quench couplings, two distinct nonequilibrium CDW states that break the underlying Z2 sublattice symmetry emerge—a quasi-coarsening CDW phase at intermediate coupling and a glassy CDW phase at large coupling. In the quasi-coarsening regime, the relaxation is governed by the annihilation of kinks, topological defects separating domains of opposite CDW order. Large-scale quench simulations reveal an anomalous temporal growth of the CDW correlation length driven by non-diffusive kink motion, in sharp contrast to the conventional reaction–diffusion mechanism that characterizes standard one-dimensional coarsening. These findings uncover a new class of nonequilibrium relaxation phenomena in electron–lattice coupled systems, where the interplay between electronic backaction and lattice dynamics gives rise to domain-growth kinetics beyond the diffusive paradigm.