Effects of charge inhomogeneities on elementary excitations in La_{2-x}Sr_xCuO_4

TL;DR

This study investigates how charge inhomogeneities affect elementary excitations in La_{2-x}Sr_xCuO_4, revealing that local charge variations significantly influence vibrational and electronic properties, aligning with experimental observations.

Contribution

It demonstrates that incorporating local charge distribution variations explains experimental results in La_{2-x}Sr_xCuO_4, bridging local inhomogeneities with bulk spectroscopic data.

Findings

Charge inhomogeneities impact vibrational modes.

Electronic spectral widths are consistent with local charge variations.

Experimental data can be modeled by including local environment distributions.

Abstract

Purely local experimental probes of many copper oxide superconductors show that their electronic states are inhomogeneous in real space. For example, scanning tunneling spectroscopic (STS) imaging shows strong variations in real space, and according to nuclear quadrupole resonance (NQR) studies the charge distribution in the bulk varies on the nanoscale. However, the analysis of the experimental results utilizing spatially-averaged probes often ignores this fact. We have performed a detailed investigation of the doping-dependence of the energy and line width and position of the zone-boundary Cu-O bond-stretching vibration in La_{2-x}Sr_xCuO_4 by inelastic neutron scattering. Both our new results as well as previously reported angle-dependent momentum widths of the electronic spectral function detected by angle-resolved photoemission can be reproduced by including the same distribution of local environments extracted from the NQR analysis.