Universal Approach to Magnetic Second-Order Topological Insulator

Cong Chen, Zhida Song, Jian-Zhou Zhao, Ziyu Chen, Zhi-Ming Yu, Xian-Lei Sheng, and Shengyuan A. Yang
Phys. Rev. Lett. 125, 056402 – Published 30 July 2020
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Abstract

We propose a universal practical approach to realize magnetic second-order topological insulator (SOTI) materials, based on properly breaking the time reversal symmetry in conventional (first-order) topological insulators. The approach works for both three dimensions (3D) and two dimensions (2D), and is particularly suitable for 2D, where it can be achieved by coupling a quantum spin Hall insulator with a magnetic substrate. Using first-principles calculations, we predict bismuthene on EuO(111) surface as the first realistic system for a two-dimensional magnetic SOTI. We explicitly demonstrate the existence of the protected corner states. Benefitting from the large spin-orbit coupling and sizable magnetic proximity effect, these corner states are located in a boundary gap 83meV, and hence can be readily probed in experiment. By controlling the magnetic phase transition, a topological phase transition between a first-order TI and a SOTI can be simultaneously achieved in the system. The effect of symmetry breaking, the connection with filling anomaly, and the experimental detection are discussed.

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  • Received 6 April 2020
  • Accepted 6 July 2020

DOI:https://doi.org/10.1103/PhysRevLett.125.056402

© 2020 American Physical Society

Physics Subject Headings (PhySH)

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Cong Chen1,2,*, Zhida Song3,*, Jian-Zhou Zhao4,2, Ziyu Chen1, Zhi-Ming Yu5,2, Xian-Lei Sheng1,2,†, and Shengyuan A. Yang2,6

  • 1Key Laboratory of Micro-nano Measurement-Manipulation and Physics (Ministry of Education), School of Physics, Beihang University, Beijing 100191, China
  • 2Research Laboratory for Quantum Materials, Singapore University of Technology and Design, Singapore 487372, Singapore
  • 3Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
  • 4Sichuan Co-Innovation Center for New Energetic Materials, Southwest University of Science and Technology, Mianyang 621010, China
  • 5Key Lab of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, and School of Physics, Beijing Institute of Technology, Beijing 100081, China
  • 6Center for Quantum Transport and Thermal Energy Science, School of Physics and Technology, Nanjing Normal University, Nanjing 210023, China

  • *C. C. and Z. S. contributed equally to this work.
  • xlsheng@buaa.edu.cn

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Issue

Vol. 125, Iss. 5 — 31 July 2020

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