One dimensional electronic states in mirror twin boundaries of Bi (1 1 1)

Abstract One-dimensional electronic states at mirror twin boundaries of Bi (1 1 1) were revealed by scanning tunneling microscopy/spectroscopy. Two different boundary structures were observed owing to the highly buckled lattice of Bi (1 1 1) and both of them have the one-dimensional boundary states. The boundary states only appear on zigzag boundaries. The dissipationless kink states were predicted in such highly symmetric domain wall of silicon, bilayer graphene or even some sonic crystals. The behavior of the boundary states in Bi (1 1 1) is consistent with the theory predictions of kink states. The strong spin-orbit coupling and anisotropic valleys in Bi (1 1 1) make the mirror twin boundaries an ideal platform to study the spin-valley coupling in the interacting one-dimensional electron systems.