Novel multiple-band superconductor SrPt2As2

TL;DR

This paper analyzes the electronic structure of the newly discovered superconductor SrPt2As2, revealing its unique three-dimensional Fermi surface and differences from FeAs-based superconductors, contributing to understanding its superconducting properties.

Contribution

It provides the first detailed electronic structure calculations of SrPt2As2, highlighting its distinct features compared to similar superconductors.

Findings

Fermi level crossed by Pt-5d states with As-4p admixture

Three-dimensional Fermi surface with complex sheets

Distinct electronic structure from FeAs-based superconductors

Abstract

We present LDA calculated electronic structure of recently discovered superconductor SrPt2As2 with Tc=5.2K. Despite its chemical composition and crystal structure are somehow similar to FeAs-based high-temperature superconductors, the electronic structure of SrPt2As2 is very much different. Crystal structure is orthorhombic (or tetragonal if idealized) and has layered nature with alternating PtAs4 and AsPt4 tetrahedra slabs sandwiched with Sr ions. The Fermi level is crossed by Pt-5d states with rather strong admixture of As-4p states. Fermi surface of SrPt2As2 is essentially three dimensional, with complicated sheets corresponding to multiple bands. We compare SrPt2As2 with 1111 and 122 representatives of FeAs-class of superconductors, as well as with isovalent (Ba,Sr)Ni2As2 superconductors. Brief discussion of superconductivity in SrPt2As2 is also presented.