The Angular Dependence of Magnetoresistance in YMn₆Sn₆

YMn₆Sn₆ is a member of the ternary Kagome magnets, known for their frustration-driven ground states and novel phenomena. YMn₆Sn₆ orders in an easy plane commensurate antiferromagnetic phase below T_N = 345K, transitioning to an incommensurate double helical (DH) structure upon further cooling. With field in the ab-plane, this DH structure evolves between multiple helical and fan-like phases. Of these, the transverse conical spiral, shows a large topological Hall effect where the scalar spin chirality is stabilized by thermal fluctuation, similar to the nematic susceptibility of Fe-based superconductors¹. Electronic band structure calculations show topological character near E_F, making YMn₆Sn₆ a candidate to investigate the interplay between the electronic topology and magnetic topological properties. Here we report signatures in the magnetoresistance indicating strong coupling between the magnetic structure and the electronic band structures. Regardless of field orientation, a decrease in resistivity above 6T indicates a strong effect on the electronic properties, independent of magnetization, implying alteration of the topological electronic bands via applied field.

¹Ghimire, N. J., et al. arXiv:2007.02399 (2020).