One-dimensional spin texture of Bi(441); Quantum Spin Hall properties without a topological insulator

M. Bianchi; F. Song; S. Cooil; A. F. Monsen; E. Wahlstrom; J. A. Miwa; E. D. L. Rienks; D. A. Evans; A. Strozecka; J. I. Pascual; M. Leandersson; T. Balasubramanian; Ph. Hofmann; J. W. Wells

doi:10.1103/physrevb.91.165307

arXiv · 1506.08017

One-dimensional spin texture of Bi(441); Quantum Spin Hall properties without a topological insulator

M. Bianchi·F. Song·S. Cooil·A. F. Monsen·E. Wahlstrom·J. A. Miwa·E. D. L. Rienks·D. A. Evans·A. Strozecka·J. I. Pascual·M. Leandersson·T. Balasubramanian·Ph. Hofmann·J. W. Wells

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Abstract

The high index (441) surface of bismuth has been studied using Scanning Tunnelling Microscopy (STM), Angle Resolved Photoemission Spectroscopy (APRES) and spin-resolved ARPES. The surface is strongly corrugated, exposing a regular array of (110)-like terraces. Two surface localised states are observed, both of which are linearly dispersing in one in-plane direction ($k_x$), and dispersionless in the orthogonal in-plane direction ($k_y$), and both of which have a Dirac-like crossing at $k_x$=0. Spin ARPES reveals a strong in-plane polarisation, consistent with Rashba-like spin-orbit coupling. One state has a strong out-of-plane spin component, which matches with the miscut angle, suggesting its {possible} origin as an edge-state. The electronic structure of Bi(441) has significant similarities with topological insulator surface states and is expected to support one dimensional Quantum Spin Hall-like coupled spin-charge transport properties with inhibited backscattering, without requiring a topological insulator bulk.

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M. Bianchi, F. Song, S. Cooil, A. F. Monsen, E. Wahlstrom, J. A. Miwa, E. D. L. Rienks, D. A. Evans, A. Strozecka, J. I. Pascual, M. Leandersson, T. Balasubramanian, Ph. Hofmann, J. W. Wells. 2015-06-26. One-dimensional spin texture of Bi(441); Quantum Spin Hall properties without a topological insulator. https://doi.org/10.1103/physrevb.91.165307

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