• DOI:10.1103/PhysRevB.95.201201
• Corpus ID: 119367546

Semiconductor, topological semimetal, indirect semimetal, and topological Dirac semimetal phases of Ge 1 − x Sn x alloys

@article{Lan2017SemiconductorTS,
  title={Semiconductor, topological semimetal, indirect semimetal, and topological Dirac semimetal phases of Ge 1 − x Sn x alloys},
  author={Huang-Siang Lan and S. T. Chang and C. W. Liu},
  journal={Physical Review B},
  year={2017},
  volume={95},
  pages={201201}
}

• Huang-Siang Lan, S. T. Chang, C. W. Liu
• Published 1 December 2016
• Physics
• Physical Review B

Electronic structures of ${\mathrm{Ge}}_{1\ensuremath{-}x}{\mathrm{Sn}}_{x}$ alloys $(0\ensuremath{\le}x\ensuremath{\le}1)$ are theoretically studied by the nonlocal empirical pseudopotential method. For relaxed ${\mathrm{Ge}}_{1\ensuremath{-}x}{\mathrm{Sn}}_{x}$, a topological semimetal is found for $\mathit{\text{x}}g41%$ with gapless and band inversion at the $\mathrm{\ensuremath{\Gamma}}$ point, while there is an indirect-direct band-gap transition at $x=8.5%$. For strained ${\mathrm{Ge}}_{1\ensuremath{-}x}{\mathrm{Sn}}_{x}$ on a Ge substrate, semimetals with a negative indirect band gap appear for $xg43%$, and the strained ${\mathrm{Ge}}_{1\ensuremath{-}x}{\mathrm{Sn}}_{x}$ on Ge is always an indirect band-gap semiconductor for $xl43%$. With appropriate biaxial compressive strains, a topological Dirac semimetal is found with band inversion at $\mathrm{\ensuremath{\Gamma}}$ and one pair of Dirac cones along the [001] direction.