Resonant inelastic x-ray scattering in one-dimensional copper oxides

TL;DR

This paper theoretically investigates the Cu K-edge RIXS spectrum in one-dimensional insulating cuprates, revealing exciton formation and incident energy dependence, thus offering insights into the upper Hubbard band.

Contribution

It provides a theoretical analysis of RIXS spectra in 1D cuprates using the extended Hubbard model, highlighting exciton features and energy dependence.

Findings

Detection of excitons at large momentum transfer

Dependence of spectra on incident photon energy

RIXS as a tool to study the upper Hubbard band

Abstract

The Cu K-edge resonant inelastic x-ray scattering (RIXS) spectrum in one-dimensional insulating cuprates is theoretically examined by using the exact diagonalization technique for the extended one-dimensional Hubbard model with nearest neighbor Coulomb interaction. We find the following characteristic features that can be detectable by RIXS experiments: (i) The spectrum with large momentum transfer indicates the formation of excitons, i.e., bound states of holon and doublon. (ii) The spectrum with small momentum transfer depends on the incident photon energy. We propose that the RIXS provides a unique opportunity to study the upper Hubbard band in one-dimensional cuprates.