Topological and superconducting properties in YD3 (D=In, Sn, Tl, Pb)

Abstract

Using first-principles calculations, we explore the electron properties of YD3 (D=In, Sn, Tl, Pb) and predict that YIn3, YTl3, and YPb3 are topological superconductor candidates. In the presence of spin-orbit coupling effect, continuous band gaps for YIn3, YSn3, and YPb3 are opened between their highest occupied bands (N) and the lowest unoccupied bands (N+1), where the different Z2 invariants are obtained. Differently and specially, there are type-II Dirac points (DPs) at the high-symmetry lines in YTl3, indicating one possibility of topological Dirac semimetal. Furthermore, the nontrivial Rashba-like topological surface states are achieved at the X¯ point on the (001) surface for YIn3, YTl3, and YPb3, as well as the Fermi arcs in YTl3 connecting the DPs. In addition to the topological properties, our electron-phonon coupling calculations indicate clearly that these four intermetallics are all phonon-mediated superconductors. The calculated superconducting transition temperatures of Tc=0.96, 6.34, 2.17, and 4.37 K respectively for YIn3, YSn3, YPb3, and YTl3 agree well with experiments.

Source-reported materials — not catalogue approval

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