X-ray absorption near-edge spectra of overdoped La_2-xSr_xCuO_4 high-T_c superconductors

TL;DR

This paper models the XANES spectra of overdoped La_2-xSr_xCuO_4 superconductors using a real-space Green's function approach that incorporates strong correlations, achieving good agreement with experimental data.

Contribution

It introduces a realistic modeling method for XANES spectra of overdoped cuprates that accounts for doping-dependent strong correlation effects.

Findings

Oxygen atoms in cuprate planes dominate low-energy spectra.

Predicted XANES matches experimental results.

Apical oxygen atoms contribute little to spectra.

Abstract

We present results for realistic modeling of the x-ray absorption near edge structure (XANES) of the overdoped high-T_c superconductor La_2-xSr_xCuO_4 in the hole doping range x = 0.20-0.30. Our computations are based on a real-space Green's function approach in which strong-correlation effects are taken into account in terms of a doping-dependent self-energy. The predicted O K-edge XANES is found to be in good accord with the corresponding experimental results in this overdoped regime. We find that the low energy spectra are dominated by the contribution of O-atoms in the cuprate planes, with little contribution from apical O-atoms.