Nonequilibrium-DMFT based RIXS investigation of the two-orbital Hubbard model

TL;DR

This paper demonstrates the application of a nonequilibrium DMFT approach to compute RIXS spectra in photo-excited two-orbital Mott insulators, revealing sensitivity to electronic population changes.

Contribution

It introduces a novel nonequilibrium DMFT-based method for calculating RIXS spectra in multi-orbital systems, advancing theoretical tools for time-dependent correlated electron studies.

Findings

Feasibility of multi-orbital nonequilibrium RIXS calculations

Sensitivity of fluorescence-like features to Hubbard band populations

Observation of d-d excitation peak variations under nonequilibrium conditions

Abstract

Resonant inelastic X-ray scattering (RIXS) detects various types of high- and low-energy elementary excitations in correlated solids, and this tool will play an increasingly important role in investigations of time-dependent phenomena in photo-excited systems. While theoretical frameworks for the computation of equilibrium RIXS spectra are well established, the development of appropriate methods for nonequilibrium simulations are an active research field. Here, we apply a recently developed nonequilibrium dynamical mean field theory (DMFT) based approach to compute the RIXS response of photo-excited two-orbital Mott insulators. The results demonstrate the feasibility of multi-orbital nonequilibrium RIXS calculations and the sensitivity of the quasi-elastic fluorescence-like features and d-d excitation peaks on the nonequilibrium population of the Hubbard bands.