Anisotropic Rashba splitting in Pt-based Janus monolayers PtXY (X,Y = S, Se, or Te).

Recent studies have demonstrated the feasibility of synthesizing two-dimensional (2D) Janus materials which possess intrinsic structural asymmetry. Hence, we performed a systematic first-principles study of 2D Janus transition metal dichalcogenide (TMD) monolayers based on PtXY (X,Y = S, Se, or Te). Our calculated formation energies show that these monolayer Janus structures retain the 1T phase.

Prediction of topological Dirac semimetal in Ca-based Zintl layered compounds CaMX (M = Zn or Cd; X = N, P, As, Sb, or Bi).

Topological Dirac materials are attracting a lot of attention because they offer exotic physical phenomena. An exhaustive search coupled with first-principles calculations was implemented to investigate 10 Zintl compounds with a chemical formula of CaMX (M = Zn or Cd, X = N, P, As, Sb, or Bi) under three crystal structures: CaAlSi-, ThCrSi-, and BaCuS-type crystal phases. All of the materials were found to energetically prefer the CaAlSi-type structure based on total ground state energy calculations.