Publication detail

Mn-Rich MnSb2Te4: A Topological Insulator with Magnetic Gap Closing at High Curie Temperatures of 45–50 K

Wimmer S., Sánchez-Barriga J., Küppers P., Ney A., Schierle E., Freyse F., Caha O., Michalička J., Liebmann M., Primetzhofer D., Hoffman M., Ernst A., Otrokov M.M., Bihlmayer G., Weschke E., Lake B., Chulkov E.V., Morgenstern M., Bauer G., Springholz G., Rader O.

Original Title

Mn-Rich MnSb2Te4: A Topological Insulator with Magnetic Gap Closing at High Curie Temperatures of 45–50 K

Type

journal article in Web of Science

Language

English

Original Abstract

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.

Keywords

Topological Insulators, Magnetic gap, Quantum anomalous Hall effect

Authors

Wimmer S., Sánchez-Barriga J., Küppers P., Ney A., Schierle E., Freyse F., Caha O., Michalička J., Liebmann M., Primetzhofer D., Hoffman M., Ernst A., Otrokov M.M., Bihlmayer G., Weschke E., Lake B., Chulkov E.V., Morgenstern M., Bauer G., Springholz G., Rader O.

Released

1. 9. 2021

Publisher

Wiley-VCH GmbH, Weinheim

Location

69451 Weinheim Germany

ISBN

1521-4095

Periodical

ADVANCED MATERIALS

Number

2102935

State

Federal Republic of Germany

Pages from

1

Pages to

11

Pages count

11

URL

https://onlinelibrary.wiley.com/doi/10.1002/adma.202102935

BibTex

@article{BUT172561,
  author="Jan {Michalička}",
  title="Mn-Rich MnSb2Te4: A Topological Insulator with Magnetic Gap Closing at High Curie Temperatures of 45–50 K",
  journal="ADVANCED MATERIALS",
  year="2021",
  number="2102935",
  pages="1--11",
  doi="10.1002/adma.202102935",
  issn="1521-4095",
  url="https://onlinelibrary.wiley.com/doi/10.1002/adma.202102935"
}