@article{357f3a9f3fe748a7975f34ef6603d1bd,
title = "Weyl spin-momentum locking in a chiral topological semimetal",
abstract = "Spin-orbit coupling in noncentrosymmetric crystals leads to spin-momentum locking – a directional relationship between an electron{\textquoteright}s spin angular momentum and its linear momentum. Isotropic orthogonal Rashba spin-momentum locking has been studied for decades, while its counterpart, isotropic parallel Weyl spin-momentum locking has remained elusive in experiments. Theory predicts that Weyl spin-momentum locking can only be realized in structurally chiral cubic crystals in the vicinity of Kramers-Weyl or multifold fermions. Here, we use spin- and angle-resolved photoemission spectroscopy to evidence Weyl spin-momentum locking of multifold fermions in the chiral topological semimetal PtGa. We find that the electron spin of the Fermi arc surface states is orthogonal to their Fermi surface contour for momenta close to the projection of the bulk multifold fermion at the Γ point, which is consistent with Weyl spin-momentum locking of the latter. The direct measurement of the bulk spin texture of the multifold fermion at the R point also displays Weyl spin-momentum locking. The discovery of Weyl spin-momentum locking may lead to energy-efficient memory devices and Josephson diodes based on chiral topological semimetals.",
author = "Krieger, {Jonas A.} and Samuel Stolz and I{\~n}igo Robredo and Kaustuv Manna and McFarlane, {Emily C.} and Mihir Date and Banabir Pal and Jiabao Yang and {B. Guedes}, Eduardo and Dil, {J. Hugo} and Polley, {Craig M.} and Mats Leandersson and Chandra Shekhar and Horst Borrmann and Qun Yang and Mao Lin and Strocov, {Vladimir N.} and Marco Caputo and Watson, {Matthew D.} and Kim, {Timur K.} and Cephise Cacho and Federico Mazzola and Jun Fujii and Ivana Vobornik and Parkin, {Stuart S.P.} and Barry Bradlyn and Claudia Felser and Vergniory, {Maia G.} and Schr{\"o}ter, {Niels B.M.}",
note = "We acknowledge Diamond Light Source for time on beamline I05 under Proposals No. SI20617-1, No. SI24703-1, and No. SI26098, Swiss Light source for beamtime on ADRESS and COPHEE under Proposals No. 20212139, 20210765, 20210484, 20191797, Elettra Sincrotrone Trieste on APE-LE under Proposal No. 20215697, and MAX IV Laboratory on Bloch-B under Proposal No. 20221295. J.A.K. acknowledges support by the Swiss National Science Foundation (SNF-Grant No. P500PT_203159). S.S. acknowledges funding from the Swiss National Science Foundation under project numbers 195133 and 159690. The authors thank Sulamith Gutwein and Theresa Voigt for help with the 3d plots in Fig. a, and Oliver J. Clark, Procopi C. Constantinou, Wenxin Li, Jaime S\u00E1nchez-Barriga, and Tianlun Yu for help during the ARPES measurements. B.B. acknowledges the support of the U. S. National Science Foundation under grant DMR-1945058. M.G.V. and C.F. thanks support to the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - FOR 5249 (QUAST). M.G.V. acknowledges partial support from the European Research Council (ERC) under grant agreement no. 101020833. M.G.V. and I.R. acknowledge that this work has been financially supported by the Ministry for Digital Transformation and of Civil Service of the Spanish Government through the QUANTUM ENIA project call - Quantum Spain project, and by the European Union through the Recovery, Transformation, and Resilience Plan - NextGenerationEU within the framework of the Digital Spain 2026 Agenda. M.G.V. and I.R. acknowledge support from the Spanish Ministerio de Ciencia e Innovacion (PID2022-142008NB-I00). K.M., C.S. and C.F. acknowledge financial support by European Research Council (ERC) Advanced Grant No. 742068 (\{"}TOPMAT\{"}), Deutsche Forschungsgemeinschaft (DFG) under SFB 1143 (Project No. 247310070) and W\u00FCrzburg-Dresden Cluster of Excellence on Complexity and Topology in Quantum Matter-ct.qmat (EXC 2147, Project No. 39085490). K.M. acknowledges Max Plank Society for the funding support under Max Plank-India partner group project, and Board of Research in Nuclear Sciences (BRNS) under 58/20/03/2021-BRNS/37084/ DAE-YSRA, Science and Engineering Research Board, DST, Government of India, via grant no: CRG/2022/001826 and Aeronautics Research and Development Board (ARDB, Project No. 1992). F.M. gratefully acknowledges the SoE action of PNRR, number SOE_0000068. This work has been partly performed in the framework of the nanoscience foundry and fine analysis (NFFA-MUR Italy Progetti Internazionali) facility. N.B.M.S. was funded by the European Union (ERC Starting Grant ChiralTopMat, project number 101117424). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Council Executive Agency. Neither the European Union nor the granting authority can be held responsible for them. We acknowledge Diamond Light Source for time on beamline I05 under Proposals No. SI20617-1, No. SI24703-1, and No. SI26098, Swiss Light source for beamtime on ADRESS and COPHEE under Proposals No. 20212139, 20210765, 20210484, 20191797, Elettra Sincrotrone Trieste on APE-LE under Proposal No. 20215697, and MAX IV Laboratory on Bloch-B under Proposal No. 20221295. J.A.K. acknowledges support by the Swiss National Science Foundation (SNF-Grant No. P500PT_203159). S.S. acknowledges funding from the Swiss National Science Foundation under project numbers 195133 and 159690. The authors thank Sulamith Gutwein and Theresa Voigt for help with the 3d plots in Fig.\u00A01 a, and Oliver J. Clark, Procopi C. Constantinou, Wenxin Li, Jaime S\u00E1nchez-Barriga, and Tianlun Yu for help during the ARPES measurements. B.B. acknowledges the support of the U. S. National Science Foundation under grant DMR-1945058. M.G.V. and C.F. thanks support to the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - FOR 5249 (QUAST). M.G.V. acknowledges partial support from the European Research Council (ERC) under grant agreement no. 101020833. M.G.V. and I.R. acknowledge that this work has been financially supported by the Ministry for Digital Transformation and of Civil Service of the Spanish Government through the QUANTUM ENIA project call - Quantum Spain project, and by the European Union through the Recovery, Transformation, and Resilience Plan - NextGenerationEU within the framework of the Digital Spain 2026 Agenda. M.G.V. and I.R. acknowledge support from the Spanish Ministerio de Ciencia e Innovacion (PID2022-142008NB-I00).\u00A0K.M., C.S. and C.F. acknowledge financial support by European Research Council (ERC) Advanced Grant No. 742068 (\{"}TOPMAT\{"}), Deutsche Forschungsgemeinschaft (DFG) under SFB 1143 (Project No. 247310070) and W\u00FCrzburg-Dresden Cluster of Excellence on Complexity and Topology in Quantum Matter-ct.qmat (EXC 2147, Project No. 39085490). K.M. acknowledges Max Plank Society for the funding support under Max Plank-India partner group project, and Board of Research in Nuclear Sciences (BRNS) under 58/20/03/2021-BRNS/37084/ DAE-YSRA, Science and Engineering Research Board, DST, Government of India, via grant no: CRG/2022/001826 and Aeronautics Research and Development Board (ARDB, Project No. 1992). F.M. gratefully acknowledges the SoE action of PNRR, number SOE_0000068. This work has been partly performed in the framework of the nanoscience foundry and fine analysis (NFFA-MUR Italy Progetti Internazionali) facility. N.B.M.S. was funded by the European Union (ERC Starting Grant ChiralTopMat, project number 101117424). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Council Executive Agency. Neither the European Union nor the granting authority can be held responsible for them.",
year = "2024",
month = dec,
doi = "10.1038/s41467-024-47976-0",
language = "English (US)",
volume = "15",
journal = "Nature communications",
issn = "2041-1723",
publisher = "Nature Research",
number = "1",
}