Depth-resolved resonant inelastic x-ray scattering at a superconductor/half-metallic ferromagnet interface through standing-wave excitation

TL;DR

This paper introduces a method combining standing-wave excitation with resonant inelastic x-ray scattering to achieve depth resolution and interface sensitivity in studying orbital and magnetic excitations in oxide heterostructures, revealing interface-specific magnetic and orbital behaviors.

Contribution

The study demonstrates the application of standing-wave RIXS to multilayer heterostructures, providing layer-resolved insights into orbital and magnetic excitations at interfaces, which was not previously achievable.

Findings

SW effects on RIXS excitations observed in multilayers

Different depth distributions of excitations identified

Magnetic excitations originate from interfaces

Abstract

We demonstrate that combining standing-wave (SW) excitation with resonant inelastic x-ray scattering (RIXS) can lead to depth resolution and interface sensitivity for studying orbital and magnetic excitations in correlated oxide heterostructures. SW-RIXS has been applied to multilayer heterostructures consisting of a superconductor La$_{1.85}$Sr$_{0.15}$CuO$_{4}$(LSCO) and a half-metallic ferromagnet La$_{0.67}$Sr$_{0.33}$MnO$_{3}$ (LSMO). Easily observable SW effects on the RIXS excitations were found in these LSCO/LSMO multilayers. In addition, we observe different depth distribution of the RIXS excitations. The magnetic excitations are found to arise from the LSCO/LSMO interfaces, and there is also a suggestion that one of the dd excitations comes from the interfaces. SW-RIXS measurements of correlated-oxide and other multilayer heterostructures should provide unique layer-resolved insights concerning their orbital and magnetic excitations, as well as a challenge for RIXS theory to specifically deal with interface effects.