Doping dependence of density response and bond-stretching phonons in cuprates

TL;DR

This paper investigates how doping levels affect bond-stretching phonons in high-temperature cuprate superconductors, using a theory based on the density response of doped Mott-Hubbard insulators.

Contribution

It provides a theoretical explanation for the doping dependence of phonon anomalies in cuprates, linking them to the density response of doped Mott-Hubbard systems.

Findings

Doping influences the behavior of zone boundary phonons in cuprates.

The theory explains the anomalous doping dependence observed experimentally.

Results connect phonon anomalies to the electronic density response in doped Mott insulators.

Abstract

We explain the anomalous doping dependence of zone boundary $(\pi,0)$ and $(\pi,\pi)$ bond-stretching phonons in the high-temperature superconductor La$_{2-\delta}$Sr$_{\delta}$CuO$_4$ in the doping range $0<\delta<0.35$. Our calculations are based on a theory for the density response of doped Mott-Hubbard insulators.