A journey across excitations in functional quantum materials using resonant inelastic x-ray scattering

The past years have witnessed an increasing interest in the field of quantum materials (QM), not only thanks to their fascinating behaviour as a macroscopic manifestation of quantum mechanics, but also for the opportunities that these materials offer in terms of ‘emergence’ of functional properties (high-temperature superconductivity, quantum Hall effect, giant magnetoelectric effect, etc...). Understanding the physics behind quantum materials is thus a primary goal of condensed matter physics, both from a fundamental as well from an applied perspective, with the ultimate scope of gaining control of QM properties towards the next generation of electronics.

In this talk, I will focus on soft Resonant Inelastic X-ray Scattering (RIXS) to study excitations in QMs that are sensitive to all the electron degrees of freedom (i.e. lattice, spin, orbital and charge) and their cross-coupling, thus  revealing unique information about the key-interactions at play in the system (magnetic interaction, electron-phonon coupling, spin-orbit coupling, topology, multiferroicity, etc...).  In this regard,  I will present an overview of recent results achieved on i) ferromagnetic thin films to investigate the evolution of the spin dynamics as a function of thickness [1]; ii) a skyrmion-material revealing the site-resolved electronic and magnetic structure [2].

This work was supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences, Early Career Award Program.