Topologically entangled Rashba-split Shockley states on the surface of grey arsenic

Abstract

We discover a pair of spin-polarized surface bands on the (111) face of grey arsenic by using angle-resolved photoemission spectroscopy (ARPES). In the occupied side, the pair resembles typical nearly-free-electron Shockley states observed on noble-metal surfaces. However, pump-probe ARPES reveals that the spin-polarized pair traverses the bulk band gap and that the crossing of the pair at $\bar{\Gamma }$ is topologically unavoidable. First-principles calculations well reproduce the bands and their non-trivial topology; the calculations also support that the surface states are of Shockley type because they arise from a band inversion caused by crystal field. The results provide compelling evidence that topological Shockley states are realized on As(111).

5 pages, 4 figures

References in corpus (3)

• Topological Insulators with Inversion Symmetry
• Strong spin-orbit splitting on Bi surfaces
• Time-resolved photoemission apparatus achieving sub-20-meV energy resolution and high stability

Cited by in corpus (7)

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• Discovery of a hybrid topological quantum state in an elemental solid
• Time-, spin-, and angle-resolved photoemission spectroscopy with a 1-MHz 10.7-eV pulse laser
• Two-dimensional Topological Semimetals Protected by Symmorphic Symmetries
• Generic Approach to Intrinsic Magnetic Second-order Topological Insulators via Inverted $p-d$ Orbitals
• Magneto transport and first principle study of strong topological insulator gray Arsenic