title: Visualizing weakly bound surface Fermi arcs and their correspondence to bulk Weyl fermions.
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.
authors.affiliation: Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Rajib
authors.initials: R
authors.lastname: Batabyal
authors.affiliation: Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Noam
authors.initials: N
authors.lastname: Morali
authors.affiliation: Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Nurit
authors.initials: N
authors.lastname: Avraham
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany.
authors.forename: Yan
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany.
authors.forename: Marcus
authors.initials: M
authors.lastname: Schmidt
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Felser
authors.affiliation: Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Ady
authors.initials: A
authors.lastname: Stern
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany.
authors.forename: Binghai
authors.identifier: 0000-0003-2164-5839
authors.initials: B
authors.lastname: Yan
authors.affiliation: Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Haim
authors.initials: H
authors.lastname: Beidenkopf
mesh_terms: D000465:Algorithms; D008962:Models, Theoretical; D055585:Physical Phenomena
keywords: Weyl semimetals; fermi arcs; scanning tunneling microscopy; topological materials