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arXiv · 2501.08973

Electronic Structure of Kramers Nodal-Line Semimetal YAuGe and Anomalous Hall Effect Induced by Magnetic Rare-Earth Substitution

Takashi Kurumaji·Jorge I. Facio·Natsuki Mitsuishi·Shusaku Imajo·Masaki Gen·Motoi Kimata·Linda Ye·David Graf·Masato Sakano·Miho Kitamura·Kohei Yamagami·Kyoko Ishizaka·Koichi Kindo·Taka-hisa Arima
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Abstract

Nodal-line semimetals are a class of topological materials hosting one dimensional lines of band degeneracy. Kramers nodal-line (KNL) metals/semimetals have recently been theoretically recognized as a class of topological states inherent to all non-centrosymmetric achiral crystal lattices. We investigate the electronic structure of candidate KNL semimetal YAuGe by angle-resolved photoemission spectroscopy (ARPES) and quantum oscillations as well as by density functional theory (DFT) calculations. DFT has revealed that YAuGe hosts KNLs on the G-A-L-M plane of the Brillouin zone, that are protected by the time reversal and mirror-inversion symmetries. Through ARPES and quantum oscillations we identify signatures of hole bands enclosing the G point, and the observed splitting of quantum oscillation frequency with angle is attributed to spin-orbit-coupling-induced band splitting away from the KNLs. Furthermore, we show that the degeneracy of the nodal lines along the G-A line is lifted by the time-reversal-symmetry breaking when the Y is substituted by magnetic R ions (R = rare earth). This becomes a source of Berry curvature and contributes to the anomalous Hall effect in magnetic RAuGe. These findings establish RAuGe as a new class of KNL semimetals offering significant potential for engineering of anomalous magnetotransport properties via magnetic rare-earth substitution.

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Takashi Kurumaji, Jorge I. Facio, Natsuki Mitsuishi, Shusaku Imajo, Masaki Gen, Motoi Kimata, Linda Ye, David Graf, Masato Sakano, Miho Kitamura, Kohei Yamagami, Kyoko Ishizaka, Koichi Kindo, Taka-hisa Arima. 2025-01-15. Electronic Structure of Kramers Nodal-Line Semimetal YAuGe and Anomalous Hall Effect Induced by Magnetic Rare-Earth Substitution. https://doi.org/10.1002/advs.202501669

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