▎ 摘　　要

Based on the analysis of band structure and edge states on zigzag graphene nanoribbons (ZGNRs), we can study theoretically the origination of two minimal quantum conductance. At the two energy points -0.20 eV and 0.15 eV corresponding to the two dips of quantum conductance, the spin-polarized quantum conductance is about 45%. Furthermore, the two types of edge-localized carriers-in the opposite transport directions along the two opposite edge sides form the quantum internal loop current, which can generate one big magnetic moment. At these two energy points -0.17 eV and 0.15 eV the two induced magnetic moments are in opposite signals. (C) 2016 Elsevier B.V. All rights reserved.