Mn-rich MnSb2Te4: A topological insulator with magnetic gap closing at high Curie temperatures of 45-50 K
| Autor: | Daniel Primetzhofer, Mikhail M. Otrokov, Eugen Weschke, F. Freyse, Andreas Ney, S. Wimmer, Gustav Bihlmayer, Gerrit E. W. Bauer, Oliver Rader, B. Lake, Philipp Küppers, Marcus Liebmann, Markus Morgenstern, Martin Hoffman, Jaime Sánchez-Barriga, Gunther Springholz, Arthur Ernst, Ondrej Caha, Enrico Schierle, Jan Michalička, Evgueni V. Chulkov |
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| Přispěvatelé: | Austrian Science Fund, Helmholtz Association, Swedish Research Council, Tomsk State University, Saint Petersburg State University, Swedish Foundation for Strategic Research, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España) |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
магнитная анизотропия Te-2 FOS: Physical sciences Quantum Materials magnetization 01 natural sciences 010305 fluids & plasmas MnSb (4) Magnetization Condensed Matter::Materials Science ферромагнитный гистерезис molecular beam epitaxy магнитные топологические изоляторы спиновая поляризация 0103 physical sciences Antiferromagnetism magnetic bandgap General Materials Science 010306 general physics Condensed Matter - Materials Science Condensed matter physics Spintronics Spin polarization Mechanical Engineering Mn-Sb site exchange Materials Science (cond-mat.mtrl-sci) Condensed Matter Physics magnetic topological insulators Ferromagnetism Mechanics of Materials Topological insulator ddc:660 Curie temperature Condensed Matter::Strongly Correlated Electrons Néel temperature Den kondenserade materiens fysik |
| Zdroj: | Advanced materials. 2021. Vol. 33, № 42. P. 2102935 (1-11) Advanced Materials Advanced materials 10, 2102935 (2021). doi:10.1002/adma.202102935 Advanced materials 33(42), 2102935 (2021). doi:10.1002/adma.202102935 Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | Ferromagnetic topological insulators exhibit the quantum anomalous Hall effect, which is potentially useful for high-precision metrology, edge channel spintronics, and topological qubits. The stable 2+ state of Mn enables intrinsic magnetic topological insulators. MnBi2Te4 is, however, antiferromagnetic with 25 K Néel temperature and is strongly n-doped. In this work, p-type MnSb2Te4, previously considered topologically trivial, is shown to be a ferromagnetic topological insulator for a few percent Mn excess. i) Ferromagnetic hysteresis with record Curie temperature of 45–50 K, ii) out-of-plane magnetic anisotropy, iii) a 2D Dirac cone with the Dirac point close to the Fermi level, iv) out-of-plane spin polarization as revealed by photoelectron spectroscopy, and v) a magnetically induced bandgap closing at the Curie temperature, demonstrated by scanning tunneling spectroscopy (STS), are shown. Moreover, a critical exponent of the magnetization β ≈ 1 is found, indicating the vicinity of a quantum critical point. Ab initio calculations reveal that Mn–Sb site exchange provides the ferromagnetic interlayer coupling and the slight excess of Mn nearly doubles the Curie temperature. Remaining deviations from the ferromagnetic order open the inverted bulk bandgap and render MnSb2Te4 a robust topological insulator and new benchmark for magnetic topological insulators. The authors thank Ondrej Man for help with lamella preparation for STEM and gratefully acknowledge financial support from the Austrian Science Funds (FWF, I4493-N: P30960-N27), the Impuls- und Vernetzungsfonds der Helmholtz-Gemeinschaft (Grant No. HRSF-0067, Helmholtz-Russia Joint Research Group), the CzechNanoLab project LM2018110 funded by MEYS CR, the CEITEC Nano Research Infrastructure, the Swedish Research Council (Project No. 821-2012-5144), the Swedish Foundation for Strategic Research (Project No. RIF14-0053), the Spanish Ministerio de Ciencia e Innovación (Project No. PID2019-103910GB-I00), Tomsk State University (Project No. 8.1.01.2018), and Saint Petersburg State University (Project No. 73028629). The work was also funded by the Deutsche Forschungsgemeinschaft within SPP1666 Topological Insulators and Germany's Excellence Strategy—Cluster of Excellence Matter and Light for Quantum Computing (ML4Q) EXC 2004/1 — 390534769, and the Graphene Flagship Core 3. G.Bihlmayer gratefully acknowledges computing resources on the supercomputer JURECA at the Jülich Supercomputing Centre. Open access funding enabled and organized by Projekt DEAL. |
| Databáze: | OpenAIRE |
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