Signatures of a topological Weyl loop in Co$_3$Sn$_2$S$_2$
| Autor: | Belopolski, Ilya, Cochran, Tyler A., Tsirkin, Stepan S., Guguchia, Zurab, Yin, Jiaxin, Zhang, Songtian S., Cheng, Zijia, Liu, Xiaoxiong, Chang, Guoqing, Yang, Xian, Multer, Daniel, Kim, Timur K., Cacho, Cephise, Felser, Claudia, Neupert, Titus, Hasan, M. Zahid |
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| Rok vydání: | 2020 |
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| Druh dokumentu: | Working Paper |
| Popis: | The search for novel topological phases of matter in quantum magnets has emerged as a frontier of condensed matter physics. Here we use state-of-the-art angle-resolved photoemission spectroscopy (ARPES) to investigate single crystals of Co$_3$Sn$_2$S$_2$ in its ferromagnetic phase. We report for the first time signatures of a topological Weyl loop. From fundamental symmetry considerations, this magnetic Weyl loop is expected to be gapless if spin-orbit coupling (SOC) is strictly zero but gapped, with possible Weyl points, under finite SOC. We point out that high-resolution ARPES results to date cannot unambiguously resolve the SOC gap anywhere along the Weyl loop, leaving open the possibility that Co$_3$Sn$_2$S$_2$ hosts zero Weyl points or some non-zero number of Weyl points. On the surface of our samples, we further observe a possible Fermi arc, but we are unable to clearly verify its topological nature using the established counting criteria. As a result, we argue that from the point of view of photoemission spectroscopy the presence of Weyl points and Fermi arcs in Co$_3$Sn$_2$S$_2$ remains ambiguous. Our results have implications for ongoing investigations of Co$_3$Sn$_2$S$_2$ and other topological magnets. Comment: Co3Sn2S2; comments welcome. Manuscript unchanged, updated comment: companion paper to arXiv:2105.14034, which is published as Phys. Rev. Lett. 127, 256403 (2021) at https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.127.256403 |
| Databáze: | arXiv |
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