Superconductivity and topologically nontrivial states in noncentrosymmetric XVSe2 (X = Pb, Sn): a first-principles study

Abstract

Noncentrosymmetric superconductors are strong candidates for exploring intrinsic topological superconductivity. Here, we predict two new noncentrosymmetric superconductors SnVSe₂ and PbVSe₂ by a systematic first-principles study. These two compounds show good thermal and dynamic stabilities. Moreover, the band topology of both compounds is predicted to be nontrivial via Z₂ calculation and slab models. We also investigate the electron–phonon interactions in SnVSe₂ and PbVSe₂, indicating the T_c of SnVSe₂ and PbVSe₂ without external pressure are predicted to be ∼1.18 K and ∼0.22 K, respectively. Furthermore, the results on pressure engineering in PbVSe₂ imply that the T_c of PbVSe₂ can be tuned to 2.39 K for enhanced contributions from Pb layers under pressure up to 6.4 GPa. This work may provide new platforms for probing spin-triplet paring and may help with designing and developing new metal-intercalated transition metal dichalcogenides.