Topological phase in non-centrosymmetric material NaSnBi
  We predict that a non-centrosymmetric material NaSnBi locates in a three-dimensional non-trivial topological phase under ambient pressure based on first-principle calculations. By deriving the effective model around $\Gamma$ point, we find that the topological phase transition is driven by a Rashba spin-orbital coupling through an odd number of pairs of band touch because of a small anisotropic gap caused by quintic dispersion terms. In contrast to conventional topological insulators, the spin texture of surface Dirac cone is right-handed and the surface states are strikingly different for different surface terminations. 
Xia Dai and Congcong Le and Xianxin Wu and Shengshan Qin and Zhiping   Lin and Jiangping Hu
cond-mat.str-el cond-mat.mes-hall