Fermi surface of Ba{1-x}KxFe2As2 as probed by angle-resolved photoemission

TL;DR

This study uses high-resolution ARPES to investigate the electronic structure and Fermi surface topology of Ba1-xKxFe2As2, revealing deviations from theoretical predictions and unexpected Fermi surface features.

Contribution

It provides new experimental insights into the Fermi surface topology of Ba1-xKxFe2As2 using advanced ARPES techniques, highlighting discrepancies with existing calculations.

Findings

Detected unexpected Fermi surface topology at the Brillouin zone boundary.

Observed deviations in low energy band structure from theoretical predictions.

Identified a shallow electron-like pocket surrounded by hole-like pockets at the X point.

Abstract

Here we apply high resolution angle-resolved photoemission spectroscopy (ARPES) using a wide excitation energy range to probe the electronic structure and the Fermi surface topology of the Ba1-xKxFe2As2 (Tc = 32 K) superconductor. We find significant deviations in the low energy band structure from that predicted in calculations. A set of Fermi surface sheets with unexpected topology is detected at the Brillouin zone boundary. At the X-symmetry point the Fermi surface is formed by a shallow electron-like pocket surrounded by four hole-like pockets elongated in G-X and G-Y directions.