Resonant Inelastic X-ray Scattering (RIXS) Spectra for Ladder Cuprates

TL;DR

This paper models RIXS spectra for ladder cuprates using a simplified tight-binding approach and strong correlation effects, aligning well with experimental data.

Contribution

It introduces a two-band tight-binding model with antiferromagnetic correlations to predict RIXS spectra for ladder cuprates, simplifying complex calculations.

Findings

Model agrees with ARPES and RIXS data

Effective approximation of complex spectra

Highlights importance of strong correlations

Abstract

The ladder compound Sr$_{14}$Cu$_{24}$O$_{41}$ is of interest both as a quasi-one-dimensional analog of the superconducting cuprates and as a superconductor in its own right when Sr is substituted by Ca. In order to model resonant inelastic x-ray scattering (RIXS) spectra for this compound, we investigate the simpler SrCu$_{2}$O$_{3}$ system in which the crystal structure contains very similar ladder planes. We approximate the LDA dispersion of SrCu$_{2}$O$_{3}$ by a Cu only two-band tight-binding model. Strong correlation effects are incorporated by assuming an anti-ferromagnetic ground state. The available angle-resolved photoemission (ARPES) and RIXS data on the ladder compound are found to be in reasonable accord with our theoretical predictions.