Nodal line resonance generating the giant anomalous Hall effect of Co$_3$Sn$_2$S$_2$

• DOI: 10.48550/arxiv.2301.13726
• Publication Date: 2023-01-01
• Authors: F. Schilberth; Ming-Chun Jiang; S. Minami; M. A. Kassem; F. Mayr; J. Deisenhofer; T. Koretsune; Yoshikazu Tabata; T. Waki; H. Nakamura; G. -Y. Guo; R. Arita; I. Kézsmárki; S. Bordács
• Keywords: Line (geometry); Fermi energy

Giant anomalous Hall effect (AHE) and magneto-optical activity can emerge in magnets with topologically non-trivial degeneracies. However, identifying the specific band structure features like Weyl points, nodal lines or planes which generate response is a challenging issue. Since low-energy interband transitions govern static AHE, we addressed this question prototypical magnetic semimetal Co$_3$Sn$_2$S$_2$ also hosting by broadband polarized reflectivity Kerr spectroscopy focus on far-infrared range. In linear dichroism spectrum observe strong resonance at 40\,meV, shows up optical conductivity primarily determines thus, confirms its intrinsic origin. Our material-specific theory reproduces experimental data remarkably well that strongly tilted line segments around Fermi energy resonance. While points only give vanishing contributions, these of gapped spin-orbit coupling dominate response.