2025/01/15 by Takashi Kurumaji, Jorge I. Facio, Natsuki Mitsuishi +13 · 1 voice
Physics and Astronomy · #Astrobiology #Band gap #Computer science #Condensed matter physics #Geometry #Hall effect #Line (geometry) #Magnetic field #Materials science #Metallurgy #NODAL #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Rare earth #Rare-earth and actinide compounds #Semimetal #Substitution (logic) #Topological Materials and Phenomena #cond-mat.mtrl-sci
paper · pdf · doi:10.1002/advs.202501669
arxiv published 2025/01/15 · openalex publication_date 2025/05/08 · arxiv updated 2025/05/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
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. The electronic structure of candidate KNL semimetal YAuGe is investigated 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 Γ-A-L-M plane of the Brillouin zone, that are protected by the time reversal and mirror-inversion symmetries. Through ARPES and quantum oscillations, signatures of hole bands enclosing the Γ point are identified, and the observed splitting of quantum oscillation frequency with angle is attributed to spin-orbit-coupling-induced band splitting away from the KNLs. Furthermore, it is shown that the degeneracy of the nodal lines along the Γ-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.