Unveiling the Nontrivial Electronic Structures and\nFermi Topology of High-Temperature Kagome Ferrimagnet HoMn<sub>6</sub>Sn<sub>6</sub>

High-temperature\n(HT) kagome magnets provide important platforms\nto explore nontrivial topological physics and promising potentials\nfor spintronic applications, due to the complicated interactions among\ntheir electrons, lattices, and magnetism. Herein, the nontrivial electronic\nproperties of a HT layered kagome-magnet, HoMn<sub>6</sub>Sn<sub>6</sub>, are systematically resolved by quantum oscillation measurements\nand density functional theory (DFT) calculations. The prominent Shubnikov–de\nHaas (SdH) oscillations under pulsed high magnetic fields reveal a\nhigh quantum mobility of 0.37 m<sup>2</sup>·V<sup>–1</sup>·s<sup>–1</sup> for this HT ferrimagnet. The observed\nmultiple-frequency quantum oscillations exhibit various angular dependences,\nconsistent with DFT calculations which suggest a complex Fermi topology\nof three three-dimensional hole pockets and two electron pockets.\nThe observed π shift of the Berry phase for quantum oscillations\nunveils nontrivial topological properties in HoMn<sub>6</sub>Sn<sub>6</sub>, further confirmed by DFT calculated Dirac fermions and large\nanomalous Hall conductivity. Our findings establish HoMn<sub>6</sub>Sn<sub>6</sub> as an HT magnetic candidate for topological magnetoelectronics\nor spin quantum applications.