Valley-protected one-dimensional states in small-angle twisted bilayer graphene

Theory predicts that the application of an electric field breaks inversion symmetry AB and BA stacked domains in twisted bilayer graphene, resulting formation a triangular network one-dimensional valley-protected helical states. This two-dimensional states has been observed several studies, but direct experimental evidence electronic transport these is still lacking. In this study, we report existence small-angle graphene at room temperature. Moreover, by analyzing Fourier transforms atomically resolved scanning tunnelling microscopy images minimally provide convincing counter-propagating indeed valley protected.