The unique electronic structure of Ca10(Pt4As8)(Fe2-xPtxAs2)5 with metallic Pt4As8 layers

TL;DR

This study reveals the unique electronic structure of Ca10(Pt4As8)(Fe2-xPtxAs2)5, highlighting metallic Pt4As8 layers and distinctive Fermi surface features, advancing understanding of iron-based superconductors.

Contribution

The paper provides the first detailed ARPES analysis showing metallic Pt4As8 layers and unusual Fermi surface characteristics in this superconductor.

Findings

Pt4As8 layers contribute to a small electron-like Fermi surface

The FeAs layers resemble other iron pnictides but with unique features

The material exhibits strong two-dimensional electronic behavior

Abstract

We studied the low-lying electronic structure of the newly discovered iron-platinum-arsenide superconductor, Ca10(Pt4As8)(Fe2-xPtxAs2)5 (Tc=22 K) with angle-resolved photoemission spectroscopy. We found that the Pt4As8 layer contributes to a small electron-like Fermi surface, indicative of metallic charge reservoir layers that are rare for iron based superconductors. Moreover, the electronic structure of the FeAs-layers resembles those of other prototype iron pnictides to a large extent. However, there is only dxy-orbital originated hole-like Fermi surface near the zone center, which is rather unique for an iron pnictide superconductor with relatively high superconducting transition temperature; and the dxz and dyz originated bands are not degenerate at the zone center. Furthermore, all bands near the Fermi energy show negligible kz dependence, indicating the strong two-dimensional nature of this material. Our results indicate this material possesses rather unique electronic structure, which enriches our current knowledge of iron based superconductors.