On the character of superconductivity and topological properties of SnAs

The paper describes results of the band structure measurements of SnAs single crystals by the ARPES technique. We performed detailed analysis of isoenergetic surfaces in the vicinity and below the Fermi energy. The ARPES experimental data are consistent with theoretically predicted shape of the SnAs Fermi surface. The determined type of the Fermi surface provides the basis for estimating the Ginzburg–Landau parameter, from which it follows that SnAs is a type-I superconductor. In addition, our results of ARPES measurements confirm the presence of band splitting in the energy spectrum at the $\overline {\Gamma }$ point at electron binding energies in the range of 0.6–1.2 eV associated with spin-orbit interaction.