Spacer-Layer-Tunable Magnetism and High-Field Topological Hall Effect in Topological Insulator Heterostructures

Controlling magnetic order in magnetic topological insulators (MTIs) is a key to developing spintronic applications with MTIs and is commonly achieved by changing the magnetic doping concentration, which inevitably affects the spin-orbit coupling strength and the topological properties. Here, we demonstrate tunable magnetic properties in topological heterostructures over a wide range, from a ferromagnetic phase with a Curie temperature of around 100 K all the way to a paramagnetic phase, while keeping the overall chemical composition the same, by controlling the thickness of nonmagnetic spacer layers between two atomically thin magnetic layers. This work showcases that spacer-layer control is a powerful tool to manipulate magneto-topological functionalities in MTI heterostructures. Furthermore, the interaction between the MTI and the Cr2O3 buffer layers also leads to a robust topological Hall effect surviving up to a record-high 6 T of magnetic field, shedding light on the critical role of interfacial layers in thin-film topological materials.

Automated summary

Researchers have successfully demonstrated tunable magnetic properties in topological heterostructures by controlling the thickness of nonmagnetic spacer layers. Additionally, the interaction between the MTIs and Cr2O3 buffer layers results in a robust topological Hall effect that can withstand high magnetic fields, showcasing the critical role of interfacial layers in thin-film topological materials.