Three-dimensional topological critical Dirac semimetal in AMgBi(A= K, Rb, Cs)

Congcong Le, Shengshan Qin, Xianxin Wu, Xia Dai, Peiyuan Fu, Chen Fang, Jiangping Hu
2017 Physical review B  
We predicted that AMgBi (A=K,Rb Cs), which have the same lattice structures as the 111 family of iron-based superconductors (Na/LiFeAs), are symmetry-protected Dirac semimetals located near the boundary of type-I and type-II Dirac semimetal phases. Doping Rb or Cs into KMgBi can drive the transition between the two phases. The materials can also be turned into Weyl semimetals and topological insulators by explicitly or spontaneously breaking time-reversal symmetry and C_4 lattice symmetry respectively.
doi:10.1103/physrevb.96.115121 fatcat:p7eouji75fhl5iup2mmmvir6b4