Modulation of antichiral edge states in zigzag graphene nanoribbons by side potential

Abstract

Antichiral edge states induced by the modified Haldane model have been predicted by Colomés and Franz (Physical Review Letters, 2018, 120(8): 086603). By applying the side potential composed of a potential field, staggered electric field, and exchange field along the boundaries of zigzag graphene nanoribbons (zGNRs), we further propose other types of antichiral edge states and investigate their corresponding transport properties. It is found that the side potential could destroy one or two (spin) edge modes, eventually inducing five novel antichiral edge states. By calculating the effect of these external fields separately on the energy band of the zGNRs, the regulatory mechanism has been explained. In addition, based on these induced edge states, we also proposed the spin/charge switcher in the three-terminal device consisting of zGNRs. We believe that these results could be used for the future designs of spintronic devices.