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

Understand

The AB-BA domain wall in gapped graphene bilayers is a rare naked structure hosting topological electronic states.

• Here we show, for the first time, direct imaging of its topological edge states by using scanning tunneling 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.