Quantum transport studies of the topological semimetal candidate SrZnSb₂

Recently, the relativistic fermions hosted by square-net lattices of main group elements have attracted a lot of attentions as they display distinct properties in a large range of materials including AMnX₂ (A=alkaline earth or rare earth elements, and X=Sb/Bi) family [1, 2] and the WHM (W=Zr, Hf, or La, H=Si, Ge, Sn or Sb, and M=O, S, Se or Te) family [3]. Bradlyn, et al. have identified many other topological phases with square-net or distorted square-net lattices in space group P4/nmm or Pnma that share a similar band topology [4]. Among the proposed candidates, we did quantum transport studies on SrZnSb₂ with space group of Pnma, where the Sb layer is distorted forming zig-zag chains. Its crystal structure is identical with that of SrMnSb₂. In SrMnSb₂, the MnSb4 tetrahedral layers develop antiferromagnetic order while the Sb zig-zag chain layers can host relativistic fermions [2]. The comparison of the transport behaviors between SrZnSb₂ and SrMnSb₂ allows us to examine how magnetic ordered layers could affect the transport nature of relativistic fermions. [1] Park, et al. PRL 107, 126402 (2011) [2] Liu, et al. Nat. Mater. 16, 905–910 (2017) [3] Xu, et al. PRB 92, 205310 (2015) [4] Bradlyn, et al. Nature 547, 298–305 (2017)