Propagating Edge and Interfacial States in Corrugated Graphene: Robustness and Configurability

Abstract

Periodically strained graphene provides a versatile platform to realize moiré-like electronic structures. We show that the interplay between a strain-induced pseudomagnetic field and a displacement-field-controlled scalar potential enables the formation of isolated narrow bands. Some of the low-energy bands are topological, carrying valley-opposite Chern numbers. Remarkably, despite a vanishing total Chern number, propagating in-gap edge states emerge in various nanoribbon geometries that preserve valley symmetry. We elucidate the distinct mechanisms responsible for edge states in the zero-energy and higher-energy gaps and demonstrate their robustness against disorders, despite lacking conventional topological protection. Leveraging these properties, we propose device architectures in which a displacement field switches the zero-energy gap and its associated edge channels on and off. Furthermore, split-gate geometries generate topological interfacial states that coexist with the edge modes and can be spatially reconfigured. These results establish strain superlattices as a powerful platform for engineering topological electronic states and electronic transport.