AP Seminar - Topological Hall effect with canted spins in Kagome antiferromagnetic Mn3Ge lattice

Antiferromagnets are emerging as promising materials for next-generation spintronics, offering high storage density, robustness, and rapid dynamic [1]. Binary signaling in antiferromagnetic structures has been realized using the frustrated Kagome Mn₃X system, where X can be Ir, Pt, Sn, or Ge [2]. More recently, this system is drawing interdisciplinary interest in physics, including superconducting spintronics [3] and topological Hall effects [4].
Topological Hall effect has been achieved in Mn₃X by Berry phase engineering via either spin-glass state transition [4] or Rashba spin-orbit interaction [5]. In this study, we found a new structural phase of Mn3Ge, which is related with a magnetically soft phase, and leads to a topological Hall effect at room temperature driven by solely spin canting. These results pave the way for expanding the study of non-collinear Kagome systems to include their intrinsic non-coplanar properties.

1. T. Jungwirth et al., Antiferromagnetic spintronics, Nature Nanotechnology 11, 231-241 (2016).
2. N. Kiyohara et al., Giant Anomalous Hall Effect in the Chiral Antiferromagnet Mn3Ge, Physical Review Applied 5, 064009 (2016).
3. K.-R. Jeon et al., Long-range supercurrents through a chiral non-collinear antiferromagnet in lateral Josephson junctions, Nature Materials 20, 1358-1363 (2021).
4. P. K. Rout et al., Field-induced topological Hall effect in the noncoplanar triangular antiferromagnetic geometry of Mn3Sn, Physical Review B 99, 094430 (2019).
5. X. Liu et al., Topological Spin Textures in a Non‐Collinear Antiferromagnet System, Advanced Materials 2211634 (2023).