Direct observation of proximity-induced magnetism and spin reorientation in topological insulator on a ferrimagnetic oxide
| Autor: | Cui-Zu Chang, Jing Shi, Chi Tang, Yen Hsun Lee, Yi Fan Zhao, Yawen Liu, Minn-Tsong Lin, Hong-Ji Lin, Kui Hon Ou Yang, Kuan Chia Chiu, Chao Yao Yang, Fan Hsiu Chang |
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| Rok vydání: | 2019 |
| Předmět: |
010302 applied physics
Materials science Physics and Astronomy (miscellaneous) Condensed matter physics Magnetism Quantum anomalous Hall effect 02 engineering and technology Quantum Hall effect 021001 nanoscience & nanotechnology 01 natural sciences Condensed Matter::Materials Science Magnetic anisotropy Ferrimagnetism Topological insulator 0103 physical sciences Proximity effect (superconductivity) Curie temperature 0210 nano-technology |
| Zdroj: | Applied Physics Letters. 114:082403 |
| ISSN: | 1077-3118 0003-6951 |
| Popis: | The quantum anomalous Hall effect (QAHE) in a magnetic topological insulator system without the need of an external magnetic field becomes of great interest because of its dissipationless spin currents. The proximity effect via a magnetic adlayer is a promising strategy to bring magnetism into a topological insulator (TI) due to its boosted Curie temperature for a realistic application. In this work, a proximity-induced magnetism above 90 K in a TI, (Bi0.25Sb0.75)2Te3, on a ferrimagnetic adlayer with perpendicular magnetic anisotropy, thulium-iron-garnet (TIG), was evidenced directly by using magnetic circular dichroism. A competition between exchange couplings with different sublattice-sites was further revealed element-specifically in a temperature-driven spin-reorientation of TI, bringing an issue on magnetic inhomogeneity at the interface, which might cause difficulties in obtaining QAHE in such a TI/TIG bilayer system. Our results prove directly the robust magnetism of TI above liquid nitrogen temperatures and also give a deep insight into the mechanism of interfacial coupling in the proximity effect for the bilayer of TI and magnetic oxide, which could be essential for the design of a system with QAHE. |
| Databáze: | OpenAIRE |
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