Enhanced charge excitations in electron-doped cuprates by resonant inelastic x-ray scattering

TL;DR

This paper explores how resonant inelastic x-ray scattering (RIXS) can detect enhanced charge excitations in electron-doped cuprates, revealing asymmetries and new low-energy modes not present in hole-doped systems.

Contribution

The study provides a theoretical analysis showing RIXS's potential to observe collective charge excitations and highlights the electron-hole asymmetry in charge dynamics of cuprates.

Findings

RIXS enhances charge excitation spectral weight in electron doping

Electron-hole asymmetry leads to a new low-energy charge mode in electron-doped cuprates

Potential for RIXS to detect novel charge excitations in electron-doped systems

Abstract

Resonant inelastic x-ray scattering (RIXS) tuned for the Cu L edge is a possible tool to detect charge excitations in cuprate superconductors. We theoretically investigate the possibility for observing a collective charge excitation by the RIXS. The RIXS process via the intermediate state inevitably makes the spectral weight of charge excitation stronger in electron doping than in hole doping. Electron-hole asymmetry also appears in the dynamical charge structure factor, showing a new enhanced small-momentum low-energy mode in electron doping. These facts indicate a possibility of detecting the new charge mode by RIXS in electron-doped systems.