Revealing Dispersive Amorphous Electronic States on the Surface of a Glassy Topological Insulator

ORAL

Abstract

The typical description of amorphous electronic structure assumes that a lack of translational symmetry ensures that momentum is ill-defined. This description is so pervasive in the amorphous field of study that the density of states is assumed to be momentum-independent, serving as the full characterization of an amorphous system's electronic structure. In this work, we uncover a highly dispersive, spin-momentum locked topological surface state in amorphous Bi2Se3 using Angle Resolved Photoemission Spectroscopy. We observe a Fermi surface with repeated annuli suggesting Bloch-like repetition and analogous Brillouin-like zones. We argue that amorphous structures conserve real-space length-scales, allowing for the existence of well-defined momentum-space length-scales, warranting a re-evaluation of amorphous band structure on the most fundamental level.

*S.C. was supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE1852814 and DGE1106400 as well as the Gordon and Betty Moore Foundation's EPiQS grant GBMF4838.

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Presenters

  • Samuel Ciocys

    • University of California, Berkeley
    • Physics, University of California, Berkeley
    • Lawrence Berkeley National Laboratory
    • Department of Physics, University of California Berkeley

Authors

  • Samuel Ciocys

    • University of California, Berkeley
    • Physics, University of California, Berkeley
    • Lawrence Berkeley National Laboratory
    • Department of Physics, University of California Berkeley

  • Paul Corbae

    • Materials Science and Engineering, University of California, Berkeley

  • Quentin Marsal

    • Institut Néel
    • Institut Neel

  • Daniel Varjas

    • QuTech and Kavli Institute of Nanoscience, Delft University of Technology
    • Delft University of Technology

  • Steven Eric Zeltmann

    • Mechanical Engineering, University of California, Berkeley

  • Adolfo G Grushin

    • Institut Néel, CNRS and Université Grenoble Alpes
    • Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel
    • Institut Neel
    • CNRS Institut Néel
    • Institut Neel, CNRS and Universite Grenoble Alpes

  • Frances Hellman

    • Physics, University of California, Berkeley
    • Lawrence Berkeley National Laboratory
    • University of California Berkeley

  • Alessandra Lanzara

    • University of California, Berkeley
    • Department of Physics, University of California
    • Physics, University of California, Berkeley
    • Lawrence Berkeley National Laboratory
    • Department of Physics, University of California Berkeley
    • Physics, University of California Berkeley
    • Physics, UC Berkeley