Robust nonlinear light localization in two-dimensional quasiperiodic moiré nonlinear lattices

Moiré superlattices, a linear periodic structure superimposes its twisted pattern, provide a fertile platform for soliton excitations and manipulations under commensurate (periodic) and incommensurate (aperiodic) circumstances; nonlinear localization in purely nonlinear systems alike is, however, a hanging question. Herein, we propose a novel two-dimensional twisted nonlinear structure called moiré nonlinear lattices, and address, theoretically and numerically, the formation, structural property, and perturbed dynamics of different localized modes (solitonic structures) therein. These localized modes appear as fundamental solitons, dipoles, and vortices with topological charge s=1; and strikingly, they can be generated at almost any twisted angle (thus leading to quasiperiodic moiré nonlinear lattices) provided that the overlapped area of a single cell exceeds 18%. The novel moiré nonlinear lattices proposed here shed some new light on classes of moiré patterns families by extending to the purely nonlinear regime, and particularly, the predicted soliton physics elucidate rich and interesting nonlinear wave dynamics in periodic, quasiperiodic and aperiodic nonlinear physical systems.