Intrinsic Dirac half-metal and quantum anomalous Hall phase in a hexagonal metal-oxide lattice

Shou-juan Zhang, Chang-wen Zhang, Shu-feng Zhang, Wei-xiao Ji, Ping Li, Pei-ji Wang, Sheng-shi Li, and Shi-shen Yan
Phys. Rev. B 96, 205433 – Published 27 November 2017
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Abstract

The quantum anomalous Hall (QAH) effect has attracted extensive attention due to time-reversal symmetry broken by a staggered magnetic flux emerging from ferromagnetic ordering and spin-orbit coupling. However, the experimental observations of the QAH effect are still challenging due to its small nontrivial bulk gap. Here, based on density functional theory and Berry curvature calculations, we propose the realization of intrinsic QAH effect in two-dimensional hexagonal metal-oxide lattice, Nb2O3, which is characterized by the nonzero Chern number (C=1) and chiral edge states. Spin-polarized calculations indicate that it exhibits a Dirac half-metal feature with temperature as large as TC=392K using spin-wave theory. When the spin-orbit coupling is switched on, Nb2O3 becomes a QAH insulator. Notably, the nontrivial topology is robust against biaxial strain with its band gap reaching up to Eg=75meV, which is far beyond room temperature. A tight-binding model is further constructed to understand the origin of nontrivially electronic properties. Our findings on the Dirac half-metal and room-temperature QAH effect in the Nb2O3 lattice can serve as an ideal platform for developing future topotronics devices.

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  • Received 5 August 2017
  • Revised 3 November 2017

DOI:https://doi.org/10.1103/PhysRevB.96.205433

©2017 American Physical Society

Physics Subject Headings (PhySH)

Quantum Information, Science & TechnologyCondensed Matter, Materials & Applied Physics

Authors & Affiliations

Shou-juan Zhang1, Chang-wen Zhang1,*, Shu-feng Zhang1, Wei-xiao Ji1, Ping Li1, Pei-ji Wang1, Sheng-shi Li2, and Shi-shen Yan2

  • 1School of Physics and Technology, University of Jinan, Jinan, Shandong 250022, People's Republic of China
  • 2School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong 250100, People's Republic of China

  • *ss_zhangchw@ujn.edu.cn

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Issue

Vol. 96, Iss. 20 — 15 November 2017

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