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arXiv · 2210.13538

Kramers nodal lines and Weyl fermions in SmAlSi

Yichen Zhang·Yuxiang Gao·Xue-Jian Gao·Shiming Lei·Zhuoliang Ni·Ji Seop Oh·Jianwei Huang·Ziqin Yue·Marta Zonno·Sergey Gorovikov·Makoto Hashimoto·Donghui Lu·Jonathan D. Denlinger·Robert J. Birgeneau·Junichiro Kono·Liang Wu·Kam Tuen Law·Emilia Morosan·Ming Yi
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Abstract

Kramers nodal lines (KNLs) have recently been proposed theoretically as a special type of Weyl line degeneracy connecting time-reversal invariant momenta. KNLs are robust to spin orbit coupling and are inherent to all non-centrosymmetric achiral crystal structures, leading to unusual spin, magneto-electric, and optical properties. However, their existence in in real quantum materials has not been experimentally established. Here we gather the experimental evidence pointing at the presence of KNLs in SmAlSi, a non-centrosymmetric metal that develops incommensurate spin density wave order at low temperature. Using angle-resolved photoemission spectroscopy, density functional theory calculations, and magneto-transport methods, we provide evidence suggesting the presence of KNLs, together with observing Weyl fermions under the broken inversion symmetry in the paramagnetic phase of SmAlSi. We discuss the nesting possibilities regarding the emergent magnetic orders in SmAlSi. Our results provide a solid basis of experimental observations for exploring correlated topology in SmAlSi.

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Yichen Zhang, Yuxiang Gao, Xue-Jian Gao, Shiming Lei, Zhuoliang Ni, Ji Seop Oh, Jianwei Huang, Ziqin Yue, Marta Zonno, Sergey Gorovikov, Makoto Hashimoto, Donghui Lu, Jonathan D. Denlinger, Robert J. Birgeneau, Junichiro Kono, Liang Wu, Kam Tuen Law, Emilia Morosan, Ming Yi. 2022-10-24. Kramers nodal lines and Weyl fermions in SmAlSi. https://doi.org/10.1038/s42005-023-01257-2

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