Designing Giant Hall Response in Layered Topological Semimetals

Noncollinear and noncoplanar magnets are promising candidates for future data storage technologies. Of particular interest are materials that show electrical transport signatures originating from the magnetic order, such as Hall effect anomalies. Few materials are known to host those, and we have no clear chemical understanding of their origin.<br/>Here, we present a chemical design strategy that allowed us to discover a series of noncoplanar magnets Ln₃Sn₇ (Ln = Tb, Dy). Our strategy is based on targeting materials that combine several magnetic sublattices with dissimilar magnetic anisotropies, along with a square-net topological semimetal layer. Ln₃Sn₇ show high carrier mobilities upwards of 17,000 cm²/(V s), and, critically, display large anomalous Hall conductivities in excess of 40,000 S/cm, which is the highest value reported to date in a noncoplanar magnet.