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 spin-orbit-coupling strength and the very topological properties. Here, we demonstrate tunable magnetic properties in topological heterostructures over a wide range, from a ferromagnetic phase with 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 non-magnetic 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 led to 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.
@article{arxiv.2107.06805,
title = {Spacer-layer-tunable magnetism and high-field topological Hall effect in topological insulator heterostructures},
author = {Xiong Yao and Hee Taek Yi and Deepti Jain and Myung-Geun Han and Seongshik Oh},
journal= {arXiv preprint arXiv:2107.06805},
year = {2021}
}