Observation and control of maximal Chern numbers in a chiral topological semimetal
Schroter NBM, Stolz S, Manna K, De Juan F, Vergniory MG, Krieger JA, Pei D, Schmitt T, Dudin P, Kim TK, Cacho C, Bradlyn B, Borrmann H, Schmidt M, Widmer R, Strokov V, Felser C (2020)
Publication Type: Journal article
Publication year: 2020
Journal
Book Volume: 369
Pages Range: 179-183
Journal Issue: 6500
Abstract
Topological semimetals feature protected nodal band degeneracies characterized by a topological invariant known as the Chern number (C). Nodal band crossings with linear dispersion are expected to have at most |C| = 4, which sets an upper limit to the magnitude of many topological phenomena in these materials. Here, we show that the chiral crystal palladium gallium (PdGa) displays multifold band crossings, which are connected by exactly four surface Fermi arcs, thus proving that they carry the maximal Chern number magnitude of 4. By comparing two enantiomers, we observe a reversal of their Fermi-arc velocities, which demonstrates that the handedness of chiral crystals can be used to control the sign of their Chern numbers.
Involved external institutions
Paul Scherrer Institute (PSI)
Switzerland (CH)
Eidgenössische Materialprüfungs- und Forschungsanstalt (Empa) / Swiss Federal Laboratories for Materials Science & Technology
Switzerland (CH)
Max-Planck-Institut für Chemische Physik fester Stoffe (MPI CPfS) / Max Planck Institute for Chemical Physics of Solids
Germany (DE)
Donostia International Physics Center (DIPC)
Spain (ES)
University of Oxford
United Kingdom (GB)
Diamond Light Source
United Kingdom (GB)
University of Illinois at Urbana-Champaign
United States (USA) (US)
Switzerland (CH)
Eidgenössische Materialprüfungs- und Forschungsanstalt (Empa) / Swiss Federal Laboratories for Materials Science & Technology
Switzerland (CH)
Max-Planck-Institut für Chemische Physik fester Stoffe (MPI CPfS) / Max Planck Institute for Chemical Physics of Solids
Germany (DE)
Donostia International Physics Center (DIPC)
Spain (ES)
University of Oxford
United Kingdom (GB)
Diamond Light Source
United Kingdom (GB)
University of Illinois at Urbana-Champaign
United States (USA) (US)
How to cite
APA:
Schroter, N.B.M., Stolz, S., Manna, K., De Juan, F., Vergniory, M.G., Krieger, J.A.,... Felser, C. (2020). Observation and control of maximal Chern numbers in a chiral topological semimetal. Science, 369(6500), 179-183. https://doi.org/10.1126/science.aaz3480
MLA:
Schroter, Niels B. M., et al. "Observation and control of maximal Chern numbers in a chiral topological semimetal." Science 369.6500 (2020): 179-183.
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