Topological Hall Effect in Thin Films of an Antiferromagnetic Weyl Semimetal Integrated on Si

Since the large room-temperature anomalous Hall effect was discovered in noncollinear antiferromagnets, Mn₃Sn has received immense research interest as it exhibits abundant exotic physical properties including Weyl points and enormous potential for antiferromagnetic spintronic device applications. In this work, we report the emergence of the topological Hall effect in Mn₃Sn films grown on Si that is the workhorse for the modern highly integrated information technology. Importantly, through a series of systematic comparative experiments, the intriguing topological Hall effect phenomenon related to the appearance of the noncoplanar chiral spin structure is found to be induced by the Mn₃Sn/SiO₂ interface. Furthermore, it was found that the current injection to a Pt/Mn₃Sn bilayer Hall bar device can effectively manipulate the chiral spin structure of Mn₃Sn, which demonstrates the feasibility of Si-based noncollinear antiferromagnetic spintronics.