Family-Vicsek dynamical scaling and Kardar-Parisi-Zhang-like superdiffusive growth of surface roughness in a driven one-dimensional quasiperiodic model
Sreemayee Aditya, Nilanjan Roy
Abstract
The investigation of the dynamical universality classes of quantum systems is an important, and rather less explored aspect of nonequilibrium physics. In this paper, considering the out-of-equilibrium dynamics of spinless fermions in a one-dimensional quasiperiodic model with and without periodic driving, we report the existence of the dynamical one-parameter Family-Vicsek (FV) scaling of the ``quantum surface roughness'' associated with the particle-number fluctuations. In the absence of periodic driving, the model is interestingly shown to host a subdiffusive critical phase with anomalous FV scaling exponents, separated by two subdiffusive critical lines and a triple point from other phases. Our analysis on the fate of the critical phase in the presence of (interphase) driving indicates that the critical phase is quite fragile, and has a tendency to get absorbed into the delocalized or localized regimes depending on the driving parameters, especially in the slow driving limit. Interestingly, periodic driving can also conspire to show quantum Kardar-Parisi-Zhang (KPZ)-like superdiffusive dynamical behavior, which seems to have no classical counterpart. We further construct an effective Floquet Hamiltonian, which qualitatively captures this feature occurring in the driven model.