Two-dimensional rectangular tantalum carbide halides TaCX (X = Cl, Br, I): Cnovel large-gap quantum spin Hall insulators

Liujiang Zhou, Wujun Shi, Yan Sun, Bin Shao, Claudia Felser, Binghai Yan, Thomas Frauenheim

Research output: Contribution to journalArticlepeer-review

Abstract

Quantum spin Hall (QSH) insulates exist in special two-dimensional (2D) semiconductors, possessing the quantized spin-Hall conductance that are topologically protected from backscattering. Based on the first-principles calculations, we predict a novel family of QSH insulators in 2D tantalum carbide halides TaCX (X=Cl, Br, and I) with unique rectangular lattice and large direct energy gaps. The mechanism for 2DQSHeffect originates from an intrinsic d-d band inversion in the process of chemical bonding. Further, stain and intrinsic electric field can be used to tune the electronic structure and enhance the energy gap. TaCX nanoribbon, which has the single-Dirac-cone edge states crossing the bulk band gap, exhibits a linear dispersion with a high Fermi velocity comparable to that of graphene. These 2D materials with considerable nontrivial gaps promise great application potential in the new generation of dissipationless electronics and spintronics.

Original languageEnglish
Article number035018
Journal2D Materials
Volume3
Issue number3
DOIs
StatePublished - 8 Sep 2016

All Science Journal Classification (ASJC) codes

  • General Chemistry
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering
  • General Materials Science

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