Anisotropic Quantum Transport through a Single Spin Channel in the Magnetic Semiconductor EuTiO 3
| Autor: | Masashi Kawasaki, Kei S. Takahashi, Masashi Tokunaga, Sunao Shimizu, Mohammad Saeed Bahramy, Ryosuke Kurihara, Atsushi Miyake, Kazuki Maruhashi, Yoshinori Tokura |
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| Rok vydání: | 2020 |
| Předmět: |
Electron mobility
Materials science Condensed matter physics Spintronics Magnetic moment Mechanical Engineering Macroscopic quantum phenomena 02 engineering and technology Magnetic semiconductor Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Condensed Matter::Materials Science Magnetization Effective mass (solid-state physics) Ferromagnetism Mechanics of Materials Condensed Matter::Strongly Correlated Electrons General Materials Science 0210 nano-technology |
| Zdroj: | Advanced Materials. 32:1908315 |
| ISSN: | 1521-4095 0935-9648 |
| DOI: | 10.1002/adma.201908315 |
| Popis: | Magnetic semiconductors are a vital component in the understanding of quantum transport phenomena. To explore such delicate, yet fundamentally important, effects, it is crucial to maintain a high carrier mobility in the presence of magnetic moments. In practice, however, magnetization often diminishes the carrier mobility. Here, it is shown that EuTiO3 is a rare example of a magnetic semiconductor that can be desirably grown using the molecular beam epitaxy to possess a high carrier mobility exceeding 3000 cm2 V-1 s-1 at 2 K, while intrinsically hosting a large magnetization value, 7 μB per formula unit. This is demonstrated by measuring the Shubnikov-de Haas (SdH) oscillations in the ferromagnetic state of EuTiO3 films with various carrier densities. Using first-principles calculations, it is shown that the observed SdH oscillations originate genuinely from Ti 3d-t2g states which are fully spin-polarized due to their energetical proximity to the in-gap Eu 4f bands. Such an exchange coupling is further shown to have a profound effect on the effective mass and fermiology of the Ti 3d-t2g electrons, manifested by a directional anisotropy in the SdH oscillations. These findings suggest that EuTiO3 film is an ideal magnetic semiconductor, offering a fertile field to explore quantum phenomena suitable for spintronic applications. |
| Databáze: | OpenAIRE |
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