Experimental signatures of phase interference and sub-femtosecond time dynamics on the incident energy axis of resonant inelastic X-ray scattering

TL;DR

This paper investigates how phase interference and sub-femtosecond dynamics influence resonant inelastic X-ray scattering (RIXS) in Mott insulators, revealing interference patterns and excitation behaviors at different absorption edges.

Contribution

It introduces a method to analyze interference effects in RIXS and demonstrates their role in understanding excitation dynamics in correlated electron systems.

Findings

Identification of quantum interference patterns in RIXS data

Evidence of an anomalous excitation at the Mott gap edge in SrCuO2

A new function to assess constructive or destructive interference in RIXS

Abstract

Core hole resonance is used in X-ray spectroscopy to incisively probe the local electronic states of many-body systems. Here, resonant inelastic X-ray scattering (RIXS) is studied as a function of incident photon energy on Mott insulators SrCuO2 and NiO to examine how resonance states decay into different excitation symmetries at the transition metal M-, L- and K-edges. Quantum interference patterns characteristic of the two major RIXS mechanisms are identified within the data, and used to distinguish the attosecond scale scattering dynamics by which fundamental excitations of a many-body system are created. A function is proposed to experimentally evaluate whether a particular excitation has constructive or destructive interference in the RIXS cross-section, and corroborates other evidence that an anomalous excitation is present at the leading edge of the Mott gap in quasi-one dimensional SrCuO2.