Direct imaging of topological edge states at a bilayer graphene domain wall

• Published in: Nature communications Vol. 7; no. 1; pp. 11760 - 6
• Main Authors: Yin, Long-Jing, Jiang, Hua, Qiao, Jia-Bin, He, Lin
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 17.06.2016; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/119/995; 639/301/357/918; 639/925/930/2735; Asymmetry; Graphene; Graphite; Humanities and Social Sciences; Magnetic fields; multidisciplinary; Physics; Science; Science (multidisciplinary); Spectrum analysis; Beijing China; China
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms11760

The AB–BA domain wall in gapped graphene bilayers is a rare naked structure hosting topological electronic states. Although it has been extensively studied in theory, a direct imaging of its topological edge states is still missing. Here we image the topological edge states at the graphene bilayer domain wall by using scanning tunnelling microscope. The simultaneously obtained atomic-resolution images of the domain wall provide us unprecedented opportunities to measure the spatially varying edge states within it. The one-dimensional conducting channels are observed to be mainly located around the two edges of the domain wall, which is reproduced quite well by our theoretical calculations. Our experiment further demonstrates that the one-dimensional topological states are quite robust even in the presence of high magnetic fields. The result reported here may raise hopes of graphene-based electronics with ultra-low dissipation. Domain wall between gapped graphene bilayers is believed to host one-dimensional topological states, which is yet waiting for direct evidences. Here, Yin et al. report images of the AB-BA stacked bilayer graphene domain wall, providing direct evidence for topological edge states in such system.