Electronic Structure of New Multiple Band Pt-Pnictide Superconductors APt3P

TL;DR

This study uses LDA calculations to analyze the electronic structure of newly discovered Pt-pnictide superconductors APt3P, revealing their three-dimensional nature and providing insights into their superconducting properties and how doping affects Tc.

Contribution

The paper provides the first detailed electronic structure analysis of APt3P superconductors, highlighting their three-dimensionality and explaining variations in Tc through density of states and doping effects.

Findings

Electronic structure is three-dimensional, unlike Fe pnictides.

LDA calculations match experimental Sommerfeld coefficients.

Doping influences Tc via changes in the density of states at the Fermi level.

Abstract

We report LDA calculated band structure, densities of states and Fermi surfaces for recently discovered Pt-pnictide superconductors APt3P (A=Ca,Sr,La), confirming their multiple band nature. Electronic structure is essentially three dimensional, in contrast to Fe pnictides and chalcogenides. LDA calculated Sommerfeld coefficient agrees rather well with experimental data, leaving little space for very strong coupling superconductivity, suggested by experimental data on specific heat of SrPt3P. Elementary estimates show, that the values of critical temperature can be explained by rather weak or moderately strong coupling, while the decrease of superconducting transition temperature Tc from Sr to La compound can be explained by corresponding decrease of total density of states at the Fermi level N(E_F). The shape of the density of states near the Fermi level suggests that in SrPt3P electron doping (such as replacement Sr by La) decreases N(E_F) and Tc, while hole doping (e.g. partial replacement of Sr with K, Rb or Cs, if possible) would increase N(E_F) and possibly Tc.