Topological insulator (TI) states have been demonstrated in materials with narrow gap and large spin-orbit interactions (SOI). Here we demonstrate that nanoscale engineering can also give rise to a TI state, even in conventional semiconductors with sizable gap and small SOI. Based on advanced first-principles calculations combined with an effective low-energy k*p Hamiltonian, we show that the intrinsic polarization of materials can be utilized to simultaneously reduce the energy gap and enhance the SOI, driving the system to a TI state. The proposed system consists of ultrathin InN layers embedded into GaN, a layer structure that is experimentally achievable.
@article{arxiv.1205.2912,
title = {Polarization-driven topological insulator transition in a GaN/InN/GaN quantum well},
author = {M. S. Miao and Q. Yan and C. G. Van de Walle and W. K. Lou and L. L. Li and K. Chang},
journal= {arXiv preprint arXiv:1205.2912},
year = {2015}
}