Exchange biased Anomalous Hall Effect driven by frustration in a magnetic Kagome lattice*

Co₃Sn₂S₂ is a ferromagnetic Weyl semimetal that has been the subject of intense scientific interest due to its large anomalous Hall effect (AHE). We show that the coupling of this material's topological properties to its magnetic texture leads to a strongly exchange biased AHE, and argue that this is likely caused by coexistence of ferromagnetism and spin glass phases. The spin glass is being driven not by disorder, but by the geometric frustration intrinsic to the Kagome network of magnetic ions. Both phases are thought to originate from the Co spin system, in an interesting display of Exchange Bias eminating from a single magnetic phase. Magnetism plays an important role in the robustness of the QAHE in magnetically doped topological insulators, and may play a crucial role in unlocking the possibility of a QAHE in low-dimensional structures of Co₃Sn₂S₂.
arXiv:1907.06651