Unveiling the Nontrivial Electronic Structures and Fermi Topology of High-Temperature Kagome Ferrimagnet HoMn₆Sn₆

High-temperature (HT) kagome magnets provide important platforms to explore nontrivial topological physics and promising potentials for spintronic applications, due to the complicated interactions among their electrons, lattices, and magnetism. Herein, the nontrivial electronic properties of a HT layered kagome-magnet, HoMn₆Sn₆, are systematically resolved by quantum oscillation measurements and density functional theory (DFT) calculations. The prominent Shubnikov-de Haas (SdH) oscillations under pulsed high magnetic fields reveal a high quantum mobility of 0.37 m²·V^-1·s^-1 for this HT ferrimagnet. The observed multiple-frequency quantum oscillations exhibit various angular dependences, consistent with DFT calculations which suggest a complex Fermi topology of three three-dimensional hole pockets and two electron pockets. The observed π shift of the Berry phase for quantum oscillations unveils nontrivial topological properties in HoMn₆Sn₆, further confirmed by DFT calculated Dirac fermions and large anomalous Hall conductivity. Our findings establish HoMn₆Sn₆ as an HT magnetic candidate for topological magnetoelectronics or spin quantum applications.