Quantum spin Hall phase in Mo2M2C3O2 (M = Ti, Zr, Hf) MXenes

The quantum spin Hall (QSH) phase is a peculiar physical phenomenon characterized by topologically protected helical edge states, with potential applications in lower-power electronics and spintronics. Here, using first-principles calculations, we predict the QSH phase in Mo 2 M 2 C 3 O 2 (M = Ti, Z...

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Bibliographic Details
Published in:Journal of materials chemistry. C, Materials for optical and electronic devices Materials for optical and electronic devices, 2016-01, Vol.4 (48), p.11524-11529
Main Authors: Si, Chen, You, Jinxuan, Shi, Wujun, Zhou, Jian, Sun, Zhimei
Format: Article
Language:English
Subjects:
Coupling
Electron spin
Hafnium
Invariants
Mathematical analysis
Orbitals
Transition metals
Zirconium
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Summary:The quantum spin Hall (QSH) phase is a peculiar physical phenomenon characterized by topologically protected helical edge states, with potential applications in lower-power electronics and spintronics. Here, using first-principles calculations, we predict the QSH phase in Mo 2 M 2 C 3 O 2 (M = Ti, Zr, or Hf), new members with ordered structures in the family of two-dimensional transition metal carbides (MXenes). The QSH phase which is confirmed by the nontrivial Z 2 topological invariant and Dirac edge states arises from a d-d band inversion between the M-d xy , x 2 − y 2 and the Mo-d z 2 orbitals and a spin-orbital coupling (SOC)-induced splitting of the M-d xy , x 2 − y 2 orbital at the Γ point. With different M atoms, the QSH gap of Mo 2 M 2 C 3 O 2 ranges from 38 to 152 meV. These findings will broaden the scientific and technological impacts of both QSH materials and MXenes. A new family of quantum spin Hall materials characterized by topologically protected helical edge states are predicted in Mo 2 MC 2 O 3 (M = Ti, Zr, Hf) MXenes.
ISSN:2050-7526
2050-7534
DOI:10.1039/c6tc04560j