Electronic Structure of Superconducting FeSe Studied by High-Resolution Photoemission Spectroscopy

TL;DR

This study uses high-resolution photoemission spectroscopy to analyze the electronic structure of superconducting FeSe, revealing details about its valence band and Fermi level behavior relevant to its superconductivity.

Contribution

First detailed photoemission analysis of FeSe's electronic structure, highlighting deviations from calculations and temperature-dependent Fermi level suppression.

Findings

Partial densities of states assigned to valence bands

Deviation of peak near Fermi level from calculations

Suppression of spectral intensity around Fermi level upon cooling

Abstract

We have performed soft x-ray and ultrahigh-resolution laser-excited photoemission measurements on tetragonal FeSe, which was recently identified as a superconductor. Energy dependent study of valence band is compared to band structure calculations and yields a reasonable assignment of partial densities of states. However, the sharp peak near the Fermi level slightly deviates from the calculated energy position, giving rise to the necessity of self-energy correction. We have also performed ultrahigh-resolution laser photoemission experiment on FeSe and observed the suppression of intensity around the Fermi level upon cooling.