2009/08/31 by Tong Zhang, Peng Cheng, Xi Chen +13 · 5 citations
Mathematics · Physics and Astronomy · #Condensed matter physics #Geometry #Mathematics #Photonic Crystals and Applications #Physics #Random lasers and scattering media #Superconductivity #Surface (topology) #Surface states #Symmetry (geometry) #T-symmetry #Theoretical physics #Topological Materials and Phenomena #Topology (electrical circuits) #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevlett.103.266803
arxiv created 2009/10/10 · openalex publication_date 2009/12/23 · arxiv updated 2015/05/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We report direct imaging of standing waves of the nontrivial surface states of topological insulator Bi2Te3 using a scanning tunneling microscope. The interference fringes are caused by the scattering of the topological states off Ag impurities and step edges on the Bi2Te3(111) surface. By studying the voltage-dependent standing wave patterns, we determine the energy dispersion E(k), which confirms the Dirac cone structure of the topological states. We further show that, very different from the conventional surface states, backscattering of the topological states by nonmagnetic impurities is completely suppressed. The absence of backscattering is a spectacular manifestation of the time-reversal symmetry, which offers a direct proof of the topological nature of the surface states.