Quasiparticle interference of the Fermi arcs and surface-bulk connectivity of a Weyl semimetal

• Published in: Science (American Association for the Advancement of Science) Vol. 351; no. 6278; pp. 1184 - 1187
• Main Authors: Inoue, Hiroyuki, Gyenis, András, Wang, Zhijun, Li, Jian, Oh, Seong Woo, Jiang, Shan, Ni, Ni, Bernevig, B. Andrei, Yazdani, Ali
• Format: Journal Article
• Language: English
• Published: United States American Association for the Advancement of Science 11.03.2016; The American Association for the Advancement of Science; AAAS
• Subjects: CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Electrons; Laboratory Equipment; MATERIALS SCIENCE; Scanning electron microscopy; Weyl semimetals
• ISSN: 0036-8075; 1095-9203; 1095-9203
• DOI: 10.1126/science.aad8766

Weyl semimetals host topologically protected surface states, with arced Fermi surface contours that are predicted to propagate through the bulk when their momentum matches that of the surface projections of the bulk's Weyl nodes. We used spectroscopic mapping with a scanning tunneling microscope to visualize quasiparticle scattering and interference at the surface of the Weyl semimetal TaAs. Our measurements reveal 10 different scattering wave vectors, which can be understood and precisely reproduced with a theory that takes into account the shape, spin texture, and momentum-dependent propagation of the Fermi arc surface states into the bulk. Our findings provide evidence that Weyl nodes act as sinks for electron transport on the surface of these materials.