We demonstrate theoretically the coexistence of Dirac semimetal and topological insulator phases in InSb/α-Sn conventional semiconductor superlattices, based on advanced first-principles calculations combined with low-energy k⋅p theory. By proper interfaces designing, a large interface polarization emerges when the growth direction is chosen along {[}111{]}. Such an intrinsic polarized electrostatic field reduces band gap largely and invert the band structure finally, leading to emerge of the topological Dirac semimetal phase with a pair of Dirac nodes appearing along the (111) crystallographic direction near the Γ point. The surface states and Fermi arc are clearly observed in (100) projected surface. In addition, we also find a two-dimensional topological insulator phase with large nontrivial band gap approaching 70 meV, which make it possible to observe the quantum spin Hall effect at room temperature. Our proposal paves a way to realize topological nontrivial phases coexisted in conventional semiconductor superlattices by proper interface designing.
@article{arxiv.1607.04391,
title = {Topological Dirac semimetal phases in InSb/$\alpha$-Sn semiconductor superlattices},
author = {Jian-Peng Sun and Jia-ji Zhu and Dong Zhang and Kai Chang},
journal= {arXiv preprint arXiv:1607.04391},
year = {2016}
}