Role of spin-orbit coupling on the electronic structure and properties of SrPtAs

The effect of spin-orbit coupling on the electronic structure of the layered iron-free pnictide superconductor, SrPtAs, has been studied using the full potential linearized augmented plane wave method. The anisotropy in Fermi velocity, conductivity and plasma frequency stemming from the layered structure are found to be enhanced by spin-orbit coupling. The relationship between spin-orbit interaction and the lack of two-dimensional inversion in the PtAs layers is analyzed within a tight-binding Hamiltonian based on the first-principles calculations. Finally, the band structure suggests that electron doping could increase $T_c$.