▎ 摘　　要

The complex nature of filling factor nu = 0 of monolayer graphene is studied in magnetotransport experiments. As a function of perpendicular magnetic field a metal-insulator transition is observed, which is attributed to disorder-induced Landau level broadening in the canted antiferromagnetic phase. In the metallic regime a separation of the zeroth Landau level appears and signs of the quantum spin Hall effect are seen near nu = 0. In addition to local transport, nonlocal transport experiments show results being consistent with helical edge transport.