The complex nature of filling factor ν = 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 ν = 0. In addition to local transport, nonlocal transport experiments show results being consistent with helical edge transport.

中文翻译：

---

单层石墨烯ν = 0附近的螺旋边缘传输

 在磁输运实验中研究了单层石墨烯填充因子ν = 0的复杂性质。作为垂直磁场的函数，观察到金属-绝缘体跃迁，这归因于在倾斜的反铁磁相中由无序引起的朗道能级展宽。在金属状态下，出现了第零朗道能级的分离，并且在ν  = 0附近看到了量子自旋霍尔效应的征兆。除了局部输运，非局部输运实验还显示出与螺旋边缘输运相一致的结果。