Low-Energy Model and Electron-Hole Doping Asymmetry of Single-Layer Ruddlesden-Popper Iridates

TL;DR

This study investigates the electronic structure of single-layer iridates, revealing electron-hole doping asymmetry and the evolution from multi-band to one-band models, with implications for correlated electron systems.

Contribution

It provides a detailed analysis of the doping asymmetry and the transition from multi-band to one-band descriptions in iridates using first-principles and slave-boson methods.

Findings

Electron-hole doping asymmetry in iridates.

Evolution from three-band to one-band model.

Comparison of electron-doped iridates to hole-doped cuprates.

Abstract

We study the correlated electronic structure of single-layer iridates based on structurally-undistorted Ba$_2$IrO$_4$. Starting from the first-principles band structure, the interplay between local Coulomb interactions and spin-orbit coupling is investigated by means of rotational-invariant slave-boson mean-field theory. The evolution from a three-band description towards an anisotropic one-band ($J=1/2$) picture is traced. Single-site and cluster self-energies are used to shed light on competing Slater- and Mott-dominated correlation regimes. We reveal a clear asymmetry between electron and hole doping, notably in the nodal/anti-nodal Fermi-surface dichotomy at strong coupling. Electron-doped iridates appear comparable to hole-doped cuprates due to the different sign of the next-nearest-neighbor hopping $t'$.