Observation of phonons with resonant inelastic x-ray scattering

TL;DR

This paper demonstrates the first measurement of phonons using resonant inelastic x-ray scattering (RIXS) in CuO, revealing insights into electron-phonon interactions relevant for material properties.

Contribution

It introduces a novel application of RIXS to measure phonons and analyzes spectral features to understand electron-phonon coupling in cupric oxide.

Findings

First phonon measurements with RIXS at Cu K-edge

Spectral intensities linked to electron-phonon coupling

Spectra explained by core-hole lifetime and diagonalization

Abstract

Phonons, the quantum mechanical representation of lattice vibrations, and their coupling to the electronic degrees of freedom are important for understanding thermal and electric properties of materials. For the first time, phonons have been measured using resonant inelastic x-ray scattering (RIXS) across the Cu K-edge in cupric oxide (CuO). Analyzing these spectra using an ultra-short core-hole lifetime approximation and exact diagonalization techniques, we can explain the essential inelastic features. The relative spectral intensities are related to the electron-phonon coupling strengths.