中国物理B ›› 2025, Vol. 34 ›› Issue (11): 117303-117303.doi: 10.1088/1674-1056/addcd2

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Intrinsic higher-order topological states in two-dimensional honeycomb quantum spin Hall insulators

Sibin Lü(吕思彬) and Jun Hu(胡军)†   

  1. Institute of High Pressure Physics, School of Physical Science and Technology, Ningbo University, Ningbo 315211, China
  • 收稿日期:2025-04-05 修回日期:2025-05-23 接受日期:2025-05-26 发布日期:2025-11-10
  • 通讯作者: Jun Hu E-mail:hujun2@nbu.edu.cn
  • 基金资助:
    Project supported by the Program for Science and Technology Innovation Team in Zhejiang Province, China (Grant No. 2021R01004), the Six Talent Peaks Project of Jiangsu Province, China (Grant No. 2019-XCL-081), and the Startup Funding of Ningbo University and Yongjiang Recruitment Project (Grant No. 432200942).

Intrinsic higher-order topological states in two-dimensional honeycomb quantum spin Hall insulators

Sibin Lü(吕思彬) and Jun Hu(胡军)†   

  1. Institute of High Pressure Physics, School of Physical Science and Technology, Ningbo University, Ningbo 315211, China
  • Received:2025-04-05 Revised:2025-05-23 Accepted:2025-05-26 Published:2025-11-10
  • Contact: Jun Hu E-mail:hujun2@nbu.edu.cn
  • About author:2025-117303-250588.pdf
  • Supported by:
    Project supported by the Program for Science and Technology Innovation Team in Zhejiang Province, China (Grant No. 2021R01004), the Six Talent Peaks Project of Jiangsu Province, China (Grant No. 2019-XCL-081), and the Startup Funding of Ningbo University and Yongjiang Recruitment Project (Grant No. 432200942).

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摘要： The exploration of topological phases remains a cutting-edge research frontier, driven by their promising potential for next-generation electronic and quantum technologies. In this work, we employ first-principles calculations and tight-binding modeling to systematically investigate the topological properties of freestanding two-dimensional (2D) honeycomb Bi, HgTe, and Al$_{2}$O$_{3}$(0001)-supported HgTe. Remarkably, all three systems exhibit coexistence of intrinsic first- and higher-order topological insulator states, induced by spin-orbit coupling (SOC). These states manifest as topologically protected gapless edge states in one-dimensional (1D) nanoribbons and symmetry-related corner states in zero-dimensional (0D) nanoflakes. Furthermore, fractional electron charges may accumulate at the corners of armchair-edged nanoflakes. Among these materials, HgTe/Al$_{2}$O$_{3}$(0001) is particularly promising due to its experimentally feasible atomic configuration and low-energy corner states. Our findings highlight the importance of exploring higher-order topological phases in quantum spin Hall insulators and pave the way for new possibilities in device applications.

关键词: higher-order topological insulators, two-dimensional honeycomb lattice, quantum spin Hall insulators

Abstract: The exploration of topological phases remains a cutting-edge research frontier, driven by their promising potential for next-generation electronic and quantum technologies. In this work, we employ first-principles calculations and tight-binding modeling to systematically investigate the topological properties of freestanding two-dimensional (2D) honeycomb Bi, HgTe, and Al$_{2}$O$_{3}$(0001)-supported HgTe. Remarkably, all three systems exhibit coexistence of intrinsic first- and higher-order topological insulator states, induced by spin-orbit coupling (SOC). These states manifest as topologically protected gapless edge states in one-dimensional (1D) nanoribbons and symmetry-related corner states in zero-dimensional (0D) nanoflakes. Furthermore, fractional electron charges may accumulate at the corners of armchair-edged nanoflakes. Among these materials, HgTe/Al$_{2}$O$_{3}$(0001) is particularly promising due to its experimentally feasible atomic configuration and low-energy corner states. Our findings highlight the importance of exploring higher-order topological phases in quantum spin Hall insulators and pave the way for new possibilities in device applications.

Key words: higher-order topological insulators, two-dimensional honeycomb lattice, quantum spin Hall insulators

中图分类号:  (Surface states, band structure, electron density of states)

  • 73.20.At
73.22.-f (Electronic structure of nanoscale materials and related systems) 03.65.Vf (Phases: geometric; dynamic or topological)