Visualizing weakly bound surface Fermi arcs and their correspondence to bulk Weyl fermions

Batabyal R, Morali N, Avraham N, Sun Y, Schmidt M, Felser C, Stern A, Yan B, Beidenkopf H (2016)

Publication Type: Journal article

Publication year: 2016

Journal

Science Advances American Association for the Advancement of Science

Book Volume: 2

Article Number: e1600709

Journal Issue: 8

DOI: 10.1126/sciadv.1600709

Abstract

Fermi arcs are the surface manifestation of the topological nature of Weyl semimetals, enforced by the bulk-boundary correspondence with the bulk Weyl nodes. The surface of tantalum arsenide, similar to that of other members of the Weyl semimetal class, hosts nontopological bands that obscure the exploration of this correspondence. We use the spatial structure of the Fermi arc wave function, probed by scanning tunneling microscopy, as a spectroscopic tool to distinguish and characterize the surface Fermi arc bands. We find that, as opposed to nontopological states, the Fermi arc wave function is weakly affected by the surface potential: it spreads rather uniformly within the unit cell and penetrates deeper into the bulk. Fermi arcs reside predominantly on tantalum sites, from which the topological bulk bands are derived. Furthermore, we identify a correspondence between the Fermi arc dispersion and the energy and momentum of the bulk Weyl nodes that classify this material as topological. We obtain these results by introducing an analysis based on the role the Bloch wave function has in shaping quantum electronic interference patterns. It thus carries broader applicability to the study of other electronic systems and other physical processes.

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:

Batabyal, R., Morali, N., Avraham, N., Sun, Y., Schmidt, M., Felser, C.,... Beidenkopf, H. (2016). Visualizing weakly bound surface Fermi arcs and their correspondence to bulk Weyl fermions. Science Advances, 2(8). https://doi.org/10.1126/sciadv.1600709

MLA:

Batabyal, Rajib, et al. "Visualizing weakly bound surface Fermi arcs and their correspondence to bulk Weyl fermions." Science Advances 2.8 (2016).

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