@article{f0375260511042d19d99b207aad3b60f,
title = "Signatures of Weyl Fermion Annihilation in a Correlated Kagome Magnet",
abstract = "The manipulation of topological states in quantum matter is an essential pursuit of fundamental physics and next-generation quantum technology. Here we report the magnetic manipulation of Weyl fermions in the kagome spin-orbit semimetal Co3Sn2S2, observed by high-resolution photoemission spectroscopy. We demonstrate the exchange collapse of spin-orbit-gapped ferromagnetic Weyl loops into paramagnetic Dirac loops under suppression of the magnetic order. We further observe that topological Fermi arcs disappear in the paramagnetic phase, suggesting the annihilation of exchange-split Weyl points. Our findings indicate that magnetic exchange collapse naturally drives Weyl fermion annihilation, opening new opportunities for engineering topology under correlated order parameters.",
author = "Ilya Belopolski and Cochran, {Tyler A.} and Xiaoxiong Liu and Cheng, {Zi Jia} and Yang, {Xian P.} and Zurab Guguchia and Tsirkin, {Stepan S.} and Yin, {Jia Xin} and Praveen Vir and Thakur, {Gohil S.} and Zhang, {Songtian S.} and Junyi Zhang and Konstantine Kaznatcheev and Guangming Cheng and Guoqing Chang and Daniel Multer and Nana Shumiya and Maksim Litskevich and Elio Vescovo and Kim, {Timur K.} and Cephise Cacho and Nan Yao and Claudia Felser and Titus Neupert and Hasan, {M. Zahid}",
note = "Funding Information: The authors thank D. Lu and M. Hashimoto at Beamline 5-2 of the Stanford Synchrotron Radiation Lightsource (SSRL) at the SLAC National Accelerator Laboratory, CA, USA for support. The authors thank Diamond Light Source for access to Beamline I05 (SI17924, SI19313). This research used Beamline 21-ID-1 (ESM-ARPES) of the National Synchrotron Light Source II, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory under Contract No. DE-SC0012704. The authors also acknowledge use of Princeton University{\textquoteright}s Imaging and Analysis Center, which is partially supported by the Princeton Center for Complex Materials (PCCM), a National Science Foundation (NSF)-MRSEC program (DMR-2011750). Use of the Stanford Synchrotron Radiation Lightsource (SSRL), SLAC National Accelerator Laboratory, is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-76SF00515. T. A. C. acknowledges the support of the National Science Foundation Graduate Research Fellowship Program (DGE-1656466). T. N. and S. S. T. acknowledge support from the European Union Horizon 2020 Research and Innovation Program (ERC-StG-Neupert-757867-PARATOP). S. S. T. also acknowledge support from the Swiss National Science Foundation (Grant No. PP00P2-176877). X. L. acknowledges financial support from the China Scholarship Council. G. C. would like to acknowledge the support of the National Research Foundation, Singapore under its NRF Fellowship Award (NRF-NRFF13-2021-0010) and the Nanyang Assistant Professorship grant from Nanyang Technological University. M. Z. H. acknowledges visiting scientist support at Berkeley Lab (LBNL) during the early phases of this work. Work at Princeton University was supported by the Gordon and Betty Moore Foundation (Grants No. GBMF4547 and No. GBMF9461; M. Z. H.). The ARPES and theoretical work were supported by the United States Department of Energy (US DOE) under the Basic Energy Sciences programme (Grant No. DOE/BES DE-FG-02-05ER46200; M. Z. H.). G. S. T. thanks the W{\"u}rzburg-Dresden Cluster of Excellence on Complexity and Topology in Quantum Matter – ct.qmat (EXC 2147) for postdoctoral funding. C. F. acknowledges the DFG through SFB 1143 (project ID. 247310070) and the W{\"u}rzburg-Dresden Cluster of Excellence on Complexity and Topology in Quantum Matter ct.qmat (EXC2147, project ID. 39085490). Publisher Copyright: {\textcopyright} 2021 American Physical Society.",
year = "2021",
month = dec,
day = "17",
doi = "10.1103/PhysRevLett.127.256403",
language = "English (US)",
volume = "127",
journal = "Physical Review Letters",
issn = "0031-9007",
publisher = "American Physical Society",
number = "25",
}