Fermi surface topology and low-lying electronic structure of a new iron-based superconductor Ca10(Pt3As8)(Fe2As2)5

TL;DR

This study uses ARPES to analyze the electronic structure and Fermi surface of a new iron-based superconductor, revealing a fourfold symmetric band structure despite its triclinic crystal symmetry, with implications for its pairing mechanism.

Contribution

First ARPES investigation of Ca10(Pt3As8)(Fe2As2)5 revealing weak coupling between layers and unique electronic features compared to other iron-based superconductors.

Findings

Fourfold symmetric band structure observed

Absence of Dirac-cone-like Fermi dots

Weak coupling between Pt3As8 layers and FeAs layers

Abstract

We report a first study of low energy electronic structure and Fermi surface topology for the recently discovered iron-based superconductor Ca10(Pt3As8)(Fe2As2)5 (the 10-3-8 phase, with Tc = 8K), via angle-resolved photoemission spectroscopy (ARPES). Despite its triclinic crystal structure, ARPES results reveal a fourfold symmetric band structure with the absence of Dirac-cone-like Fermi dots (related to magnetism) found around the Brillouin zone corners in other iron-based superconductors. Considering that the triclinic lattice and structural supercell arising from the Pt3As8 intermediary layers, these results indicate that those layers couple only weakly to the FeAs layers in this new superconductor, which has implications for the determination of its potentially novel pairing mechanism.