Resolving the topological classification of bismuth with topological defects

Nayak AK, Reiner J, Queiroz R, Fu H, Shekhar C, Yan B, Felser C, Avraham N, Beidenkopf H (2019)

Publication Type: Journal article

Publication year: 2019

Journal

Science Advances American Association for the Advancement of Science

Book Volume: 5

Article Number: eaax6996

Journal Issue: 11

DOI: 10.1126/sciadv.aax6996

Abstract

The growing diversity of topological classes leads to ambiguity between classes that share similar boundary phenomenology. This is the status of bulk bismuth. Recent studies have classified it as either a strong or a higher-order topological insulator, both of which host helical modes on their boundaries. We resolve the topological classification of bismuth by spectroscopically mapping the response of its boundary modes to a screw-dislocation. We find that the one-dimensional mode, on step-edges, extends over a wide energy range and does not open a gap near the screw-dislocations. This signifies that this mode binds to the screw-dislocation, as expected for a material with nonzero weak indices. We argue that the small energy gap, at the time reversal invariant momentum L, positions bismuth within the critical region of a topological phase transition between a higher-order topological insulator and a strong topological insulator with nonzero weak indices.

Involved external institutions

Weizmann Institute of Science IL Israel (IL) Max-Planck-Institut für Chemische Physik fester Stoffe (MPI CPfS) / Max Planck Institute for Chemical Physics of Solids DE Germany (DE)

How to cite

APA:

Nayak, A.K., Reiner, J., Queiroz, R., Fu, H., Shekhar, C., Yan, B.,... Beidenkopf, H. (2019). Resolving the topological classification of bismuth with topological defects. Science Advances, 5(11). https://doi.org/10.1126/sciadv.aax6996

MLA:

Nayak, Abhay Kumar, et al. "Resolving the topological classification of bismuth with topological defects." Science Advances 5.11 (2019).

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