Effects of electronic correlation on X-Ray absorption and dichroic spectra at L$_{2,3}$ edge

TL;DR

This paper introduces a new theoretical method to incorporate electronic correlations in X-ray absorption and dichroic spectra, accurately reproducing experimental line shapes and satellite features at the L2,3 edges of transition metals.

Contribution

A unified theoretical approach that includes many-body effects in both charged and neutral excitations for X-ray spectra analysis.

Findings

Many-body effects are essential for accurate spectral line shapes.

The approach reproduces satellite structures in core level photoemission.

Asymmetric line shapes are explained by including correlations.

Abstract

We present a new theoretical approach to describe X-Ray absorption and Magnetic Circular Dichroism spectra in the presence of e-e correlation. Our approach provides an unified picture to include correlations in both charged and neutral excitations, namely in direct / inversion photoemission where electrons are removed/added, and photo absorption where electrons are promoted from core levels to empty states. We apply this approach to the prototypical case of L$_{2,3}$ edge of 3$d$ transition metals and we show that the inclusion of many body effects in the core level excitations is essential to reproduce, together with satellite structures in core level photoemission, the observed asymmetric line shapes in X-ray absorption and dichroic spectra.