Fermi Arcs vs. Fermi Pockets in Electron-doped Perovskite Iridates

TL;DR

This study uses ARPES to investigate the electronic structure of electron-doped perovskite iridates, revealing Fermi pockets and arcs influenced by electronic and structural factors, advancing understanding of their complex Fermi surface topology.

Contribution

It provides the first detailed ARPES characterization of bulk electron-doped (Sr1-xLax)3Ir2O7, highlighting the coexistence of Fermi arcs, pockets, and structural effects.

Findings

Fermi surface pockets match expected electron count from La doping

Fermi arcs observed depend on photon energy and polarization

Spectral variations suggest coexistence of electronic supermodulation and structural distortion

Abstract

We report on an angle resolved photoemission (ARPES) study of bulk electron-doped perovskite iridate, (Sr1-xLax)3Ir2O7. Fermi surface pockets are observed with a total electron count in keeping with that expected from La substitution. Depending on the energy and polarization of the incident photons, these pockets show up in the form of disconnected "Fermi arcs", reminiscent of those reported recently in surface electron-doped Sr2IrO4. Our observed spectral variation is consistent with the coexistence of an electronic supermodulation with structural distortion in the system.