Prediction of Near-Room-Temperature Quantum Anomalous Hall Effect on Honeycomb Materials

Shu-Chun Wu, Guangcun Shan, and Binghai Yan
Phys. Rev. Lett. 113, 256401 – Published 15 December 2014
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Abstract

Recently, the long-sough quantum anomalous Hall effect was realized in a magnetic topological insulator. However, the requirement of an extremely low temperature (approximately 30 mK) hinders realistic applications. Based on ab initio band structure calculations, we propose a quantum anomalous Hall platform with a large energy gap of 0.34 and 0.06 eV on honeycomb lattices comprised of Sn and Ge, respectively. The ferromagnetic (FM) order forms in one sublattice of the honeycomb structure by controlling the surface functionalization rather than dilute magnetic doping, which is expected to be visualized by spin polarized STM in experiment. Strong coupling between the inherent quantum spin Hall state and ferromagnetism results in considerable exchange splitting and, consequently, an FM insulator with a large energy gap. The estimated mean-field Curie temperature is 243 and 509 K for Sn and Ge lattices, respectively. The large energy gap and high Curie temperature indicate the feasibility of the quantum anomalous Hall effect in the near-room-temperature and even room-temperature regions.

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  • Received 19 May 2014

DOI:https://doi.org/10.1103/PhysRevLett.113.256401

© 2014 American Physical Society

Authors & Affiliations

Shu-Chun Wu1, Guangcun Shan1, and Binghai Yan1,2,*

  • 1Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
  • 2Max Planck Institute for Physics of Complex Systems, D-01187 Dresden, Germany

  • *yan@cpfs.mpg.de

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Issue

Vol. 113, Iss. 25 — 19 December 2014

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