TY - JOUR
T1 - Emerging chiral edge states from the confinement of a magnetic Weyl semimetal in Co3Sn2 S2
AU - Muechler, Lukas
AU - Liu, Enke
AU - Gayles, Jacob
AU - Xu, Qiunan
AU - Felser, Claudia
AU - Sun, Yan
N1 - Funding Information:
This work was financially supported by the ERC Advanced Grant No. 29147z “Idea Heusler,” ERC Advanced Grant No. 742068-TOPMAT, and Deutsche Forschungsgemeinschaft DFG under Grant No. SFB 1143. E.L. acknowledges support from the Alexander von Humboldt Foundation of Germany for his Fellowship and from thew National Natural Science Foundation of China for his Excellent Young Scholarship (Grant No. 51722106). L.M. would like to thank the MPI CPFS where part of the work was performed, and the authors thank B. Yan for helpful discussions. The Flatiron Institute is a division of the Simons Foundation. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by the Max Planck Society.
Publisher Copyright:
© 2020 American Physical Society.
PY - 2020/3/15
Y1 - 2020/3/15
N2 - The quantum anomalous Hall effect (QAHE) and magnetic Weyl semimetals (WSMs) are topological states induced by intrinsic magnetic moments and spin-orbit coupling. Their similarity suggests the possibility of achieving the QAHE by dimensional confinement of a magnetic WSM along one direction. In this paper, we investigate the emergence of the QAHE in the two-dimensional (2D) limit of magnetic WSMs due to finite-size effects in thin films and step edges. We demonstrate the feasibility of this approach with effective models and real materials. To this end, we have chosen the layered magnetic WSM Co3Sn2S2, which features a large anomalous Hall conductivity and anomalous Hall angle in its three-dimensional bulk as our material candidate. In the 2D limit of Co3Sn2S2, two QAHE states exist depending on the stoichiometry of the 2D layer. One is a semimetal with a Chern number of 6, and the other is an insulator with a Chern number of 3. The latter has a band gap of 0.05 eV, which is much larger than that in magnetically doped topological insulators. Our findings naturally explain the existence of chiral states in step edges of bulk Co3Sn2S2 which have been reported in a recent experiment at T=4K and present a realistic avenue to realize QAH states in thin films of magnetic WSMs.
AB - The quantum anomalous Hall effect (QAHE) and magnetic Weyl semimetals (WSMs) are topological states induced by intrinsic magnetic moments and spin-orbit coupling. Their similarity suggests the possibility of achieving the QAHE by dimensional confinement of a magnetic WSM along one direction. In this paper, we investigate the emergence of the QAHE in the two-dimensional (2D) limit of magnetic WSMs due to finite-size effects in thin films and step edges. We demonstrate the feasibility of this approach with effective models and real materials. To this end, we have chosen the layered magnetic WSM Co3Sn2S2, which features a large anomalous Hall conductivity and anomalous Hall angle in its three-dimensional bulk as our material candidate. In the 2D limit of Co3Sn2S2, two QAHE states exist depending on the stoichiometry of the 2D layer. One is a semimetal with a Chern number of 6, and the other is an insulator with a Chern number of 3. The latter has a band gap of 0.05 eV, which is much larger than that in magnetically doped topological insulators. Our findings naturally explain the existence of chiral states in step edges of bulk Co3Sn2S2 which have been reported in a recent experiment at T=4K and present a realistic avenue to realize QAH states in thin films of magnetic WSMs.
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U2 - 10.1103/PhysRevB.101.115106
DO - 10.1103/PhysRevB.101.115106
M3 - Article
AN - SCOPUS:85083276792
SN - 2469-9950
VL - 101
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
IS - 11
M1 - 115106
ER -