Polarized resonant inelastic x-ray scattering as an ultra-fine probe of excited states in La2CuO4

TL;DR

This study demonstrates that polarized resonant inelastic x-ray scattering at the Cu K-edge in La2CuO4 provides an ultra-fine probe of the local environment and electronic structure, revealing non-local effects with high sensitivity.

Contribution

First application of combined ab initio and many-body cluster calculations to interpret polarized RIXS data in La2CuO4, highlighting non-local Cu 3d state transitions.

Findings

High sensitivity of RIXS to Cu atom environment

Identification of off-site Cu 3d state transitions

Excellent agreement between calculations and experiment

Abstract

X-ray absorption is the standard method to probe the unoccupied density of states at a given edge. Here we show that polarized Resonant Inelastic X-Ray Scattering in La2CuO4 at the Cu K-edge is extremely sensitive to the environment of the Cu atom and the fine structure in the Cu 4p density of states. Combined ab initio and many-body cluster calculations, used for the first time in such a context, show remarkable agreement with experiment. In particular we identify a non-local effect namely a transition to off-site Cu 3d states.