Helical-edge transport near ν = 0 of monolayer graphene

• Published in: Current applied physics Vol. 27; pp. 25 - 30
• Main Authors: Hong, Sung Ju, Belke, Christopher, Rode, Johannes C., Brechtken, Benedikt, Haug, Rolf J.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2021; 한국물리학회
• Subjects: Disorder; Graphene; Helical transport; Landau level broadening; ν = 0; 물리학; Graphene; Disorder; Landau level broadening; Helical transport; ν = 0
• ISSN: 1567-1739; 1878-1675
• DOI: 10.1016/j.cap.2021.04.001

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. [Display omitted] •A metal-insulator transition with perpendicular magnetic field was observed at ν = 0 of monolayer graphene.•The insulating phase is understood by canted antiferromagnetic phase as previously reported.•The metallic phase results from gap closing of canted antiferromagnetic phase due to disorder-induced Landau level broadening.•A nonlocal transport results also support the helical transport of ν = 0 of monolayer graphene.