@article{6f4c7a18863d41d28d92a49a6da1ae41,
title = "Observation and control of maximal Chern numbers in a chiral topological semimetal",
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.",
author = "Schr{\"o}ter, {Niels B.M.} and Samuel Stolz and Kaustuv Manna and {De Juan}, Fernando and Vergniory, {Maia G.} and Krieger, {Jonas A.} and Ding Pei and Thorsten Schmitt and Pavel Dudin and Kim, {Timur K.} and Cephise Cacho and Barry Bradlyn and Horst Borrmann and Marcus Schmidt and Roland Widmer and Strocov, {Vladimir N.} and Claudia Felser",
note = "K.M. and C.F. acknowledge financial support from the European Research Council (ERC) Advanced Grant nos. 291472 \{"}Idea Heusler\{"} and 742068 \{"}TOP-MAT\{"}, and Deutsche Forschungsgemeinschaft (project ID 258499086 and FE 633/30-1). N.B.M.S. was supported by Microsoft. M.G.V. acknowledges support from DFG INCIEN2019-000356 from Gipuzkoako Foru Aldundia. S.S. and R.W. acknowledge funding from the Swiss National Science Foundation under SNSF project number 159690. D.P. acknowledges support from the Chinese Scholarship Council. J.A.K. acknowledges support from the Swiss National Science Foundation (SNF-grant no. 200021-165910).",
year = "2020",
month = jul,
day = "10",
doi = "10.1126/science.aaz3480",
language = "English (US)",
volume = "369",
pages = "179--183",
journal = "Science",
issn = "0036-8075",
publisher = "American Association for the Advancement of Science",
number = "6500",
}