Electronic structure of Fe1.04(Te0.66Se0.34)

TL;DR

This study investigates the electronic structure of Fe1.04(Te0.66Se0.34) using photoemission spectroscopy and density functional theory, revealing similarities and key differences with iron-pnictides, especially near the Gamma-point.

Contribution

First combined high-resolution ARPES and DFT analysis of Fe1.04(Te0.66Se0.34), highlighting its electronic structure and differences from iron-pnictides.

Findings

Three distinct bands cross the Fermi level near the zone center.

Presence of a hole-like elliptical Fermi surface at the zone center.

No evidence of spin density wave in the electronic structure.

Abstract

We report the electronic structure of the iron-chalcogenide superconductor, Fe1.04(Te0.66Se0.34), obtained with high resolution angle-resolved photoemission spectroscopy and density functional calculations. In photoemission measurements, various photon energies and polarizations are exploited to study the Fermi surface topology and symmetry properties of the bands. The measured band structure and their symmetry characters qualitatively agree with our density function theory calculations of Fe(Te0.66Se0.34), although the band structure is renormalized by about a factor of three. We find that the electronic structures of this iron-chalcogenides and the iron-pnictides have many aspects in common, however, significant differences exist near the Gamma-point. For Fe1.04(Te0.66Se0.34), there are clearly separated three bands with distinct even or odd symmetry that cross the Fermi energy (EF) near the zone center, which contribute to three hole-like Fermi surfaces. Especially, both experiments and calculations show a hole-like elliptical Fermi surface at the zone center. Moreover, no sign of spin density wave was observed in the electronic structure and susceptibility measurements of this compound.