Chiral topological semimetal with multifold band crossings and long Fermi arcs

DOI: 10.1038/s41567-019-0511-y

Authors: Niels B. M. Schröter (Swiss Light Source) , Ding Pei (University of Oxford) , Maia G. Vergniory (Donostia International Physics Center; IKERBASQUE, Basque Foundation for Science) , Yan Sun (Max Planck Institute for Chemical Physics of Solids) , Kaustuv Manna (Max Planck Institute for Chemical Physics of Solids) , Fernando De Juan (Donostia International Physics Center; IKERBASQUE, Basque Foundation for Science; University of Oxford) , Jonas A. Krieger (Swiss Light Source; Paul Scherrer Institute; ETH Zurich) , Vicky Süss (Max Planck Institute for Chemical Physics of Solids, Dresden) , Marcus Schmidt (Max Planck Institute for Chemical Physics of Solids) , Pavel Dudin (Diamond Light Source) , Barry Bradlyn (University of Illinois at Urbana-Champaign) , Timur K. Kim (Diamond Light Source) , Thorsten Schmitt (Swiss Light Source) , Cephise Cacho (Diamond Light Source) , Claudia Felser (Max Planck Institute for Chemical Physics of Solids) , Vladimir N. Strocov (Swiss Light Source) , Yulin Chen (University of Oxford)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Nature Physics , VOL 353

State: Published (Approved)
Published: May 2019
Diamond Proposal Number(s): 19883 , 21400

Abstract: Topological semimetals in crystals with a chiral structure (which possess a handedness due to a lack of mirror and inversion symmetries) are expected to display numerous exotic physical phenomena, including fermionic excitations with large topological charge1, long Fermi arc surface states2,3, unusual magnetotransport4 and lattice dynamics5, as well as a quantized response to circularly polarized light6. So far, all experimentally confirmed topological semimetals exist in crystals that contain mirror operations, meaning that these properties do not appear. Here, we show that AlPt is a structurally chiral topological semimetal that hosts new four-fold and six-fold fermions, which can be viewed as a higher spin generalization of Weyl fermions without equivalence in elementary particle physics. These multifold fermions are located at high symmetry points and have Chern numbers larger than those in Weyl semimetals, thus resulting in multiple Fermi arcs that span the full diagonal of the surface Brillouin zone. By imaging these long Fermi arcs, we experimentally determine the magnitude and sign of their Chern number, allowing us to relate their dispersion to the handedness of their host crystal.

Journal Keywords: Electronic properties and materials; Topological matter

Subject Areas: Physics, Materials


Instruments: I05-ARPES

Added On: 14/05/2019 14:08

Discipline Tags:

Quantum Materials Hard condensed matter - electronic properties Physics Materials Science

Technical Tags:

Spectroscopy Angle Resolved Photoemission Spectroscopy (ARPES) High Resolution ARPES (HR-ARPES) Nano ARPES