▎ 摘　　要

Graphene features topological edge bands that connect a pair of Dirac points through either sector of the one-dimensional Brillouin zone depending on edge configurations (zigzag or bearded). Because of their flat dispersion, spontaneous edge magnetization can arise from Coulomb interaction in graphene nanoribbons, which has caught a remarkable amount of interest in graphene spintronics. We find an anomalous Bloch oscillation in such edge bands, in which the flat dispersion freezes electron motion along the field direction, while the topological connection of the bands through the bulk leads to electron oscillation in the transverse direction between opposite sides or layers of a bilayer ribbon. Our Hubbard-model mean-field calculation shows that this phenomenon can be exploited for electrical switching of edge magnetization configurations.