Tailoring Hybrid Anomalous Hall Response in Engineered Magnetic Topological Insulator Heterostructures

Magnetic topological insulators (MTIs) have greatly broadened the research scope of topological quantum materials. Introducing MTIs into the field of spintronics defines a new trend of magnetic-based logic and memory applications. Engineering the anomalous Hall effect (AHE) in emerging MTIs has great potentials for quantum information processing and spintronics applications.
In this talk, we will present the MBE growth and exotic transport properties of Bi2Te3/MnTe heterostructures. RHEED, XRR and TEM have revealed the high quality and atomically flat interface of the film. Through transport measurements, we observed pronounced AHE signals from both layers combined together The evolution of the resulting hybrid AHE intensity with the top Bi2Te3 layer thickness manifests the presence of an intrinsic ferromagnetic phase induced by the topological surface states at the heterolayer-interface. Surprisingly, we find the polarity of AHE can be switched by adjusting the Fermi level position of the Bi2Te3 layer via effective Sb-doping. Such flexibility in controlling the AHE strength, which depend on the specific band structure (i.e., Berry curvature), in our MTI heterostructures therefore opens up a multitude of opportunities to explore MTI-based spintronics devices.