Recently, the topological classification of electronic states has been extended to a new class of matter known as topological crystalline insulators. Similar to topological insulators, topological crystalline insulators also have spin-momentum locked surface states; but they only exist on specific crystal planes that are protected by crystal reflection symmetry. Here, we report an ultra-low temperature scanning tunneling microscopy and spectroscopy study on topological crystalline insulator SnTe nanoplates grown by molecular beam epitaxy. We observed quasiparticle interference patterns on the SnTe (001) surface that can be interpreted in terms of electron scattering from the four Fermi pockets of the topological crystalline surface states in the first surface Brillouin zone. Our quantitative analysis of the energy resolved quasiparticle interference patterns indicates the observation of the second Dirac point beyond the Lifshitz transition. A comparison between the experimental and computed quasiparticle interference patterns reveals possible spin texture of the surface states.
Citation: Physical Review B
Pub Type: Journals
Quasiparticle scattering, scanning tunneling microscopy, scanning tunneling spectroscopy, SnTe, topological insulator