Prediction of Dirac line semi-metallic phase in HfSnTe: a first-principles study

Fehmeeda Shaheen^1*, Ina Marie R. Verzola¹, Sreeparvathy P. C^1,2, Rovi Angelo B. Villaos¹, Zhi-Quan Huang¹, Feng-Chuan Chuang^1,2,3,4

¹Department of Physics, National Sun Yat-sen University, Kaohsiung, Taiwan
²Physics Division, National Center for Theoretical Sciences, Taipei, Taiwan
³Center for Theoretical and Computational Physics, National Sun Yat-sen University, Kaohsiung, Taiwan
⁴Department of Physics, National Tsing Hua University, Hsinchu, Taiwan

* Presenter:Fehmeeda Shaheen, email:fehmeedas92@gmail.com

Topological semimetals with distinctive band crossings near the Fermi level, which enable Dirac-node-like zero-dimensional (0D) and Dirac line or loop-type (1D) degeneracies, have gathered huge research interest due to their intriguing quantum transport properties. A plethora of materials have been reported without (SOC) to be Dirac line however, most of them eventually transform into topological phases under SOC. For this reason, exploring the ideal Dirac line material phase preserved under SOC is still of enormous research interest. In this work, we employ DFT calculations for the investigation of the structural, electronic, and topological properties of HfSnTe and the other WHM compounds (W = Zr or Hf; H = Sn or Pb; M = S, Se, or Te), totaling twelve compounds. The electronic band structures of HfSnTe under the (HSE06) with SOC show the Dirac nodal line on the kz = 0.5 plane and tiny gapped Dirac nodes on the kz = 0 plane near the Fermi level. In addition, a symmetry-protected Dirac line was found along the kz direction (X-R and A-M high-symmetry paths). The topological surface states and surface arcs are further calculated to confirm these Dirac features. some materials exhibit Dirac nodal-line semimetal properties while HfPbSe displays TCI.

Keywords: Tetragonal materials , Dirac line semimetals,, topological semimetals