Inelastic X-ray scattering as a probe for magnetic excitation in the iron arsenides and beyond

• Grant number: 16/22471-3
• Support Opportunities: Scholarships abroad - Research
• Start date: April 17, 2017
• End date: June 16, 2017
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Fernando Assis Garcia
• Grantee: Fernando Assis Garcia
• Host Investigator: Johan Chang
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: University of Zurich (UZH), Switzerland

Abstract

X rays scattering close to the resonant condition provides element sensitivity and accurate structural informationof solid state systems. In principle, the inelastic component of the scattering contains valuable informationabout the many elementary excitations in the solid under investigation. Current developments of beam linetechnologies made possible these studies employing synchrotron based x-rays, that were previously available,with all its caveats, only by means of neutrons scattering experiments. These excitations are important for theycan be related to the onset of very diverse phenomena, ranging from superconductivity and band topology, bothof which at the core of discussions concerning the physics of correlated electron systems.This project proposes the investigation of 3d and 4f correlated electron systems by resonant inelastic x raysscattering (RIXS). Our purpose is to characterize the Fe 3d orbital conguration and excitations in the ironarsenide BaFe2ÀýxMnxAs2, as well as the Ce 4f orbitals in the skutterudite CeFe4P12.In the case of the iron arsenide, our proposal is an attempt to understand the role of local moments in thequenching of the superconducting state observed for Mn substituted samples. Such information is consideredkey to understand the role of magnetic excitations in the context of superconductivity in the arsenides. In thecase of the skutterudite, we propose to investigate the symmetry of the crystal eld ground state and magneticexcitations and to connect it to the topology of their electronic structure.No less important, it is also the goal of this project to add new x rays based techniques to our group portfolio,having in mind the new state of art instrumentation that will be available in the upcoming Sirius light source.The overall schedule of this project covers one year and a half of research activities (experiments, data analysisand the presentation of the results), including a one year period at the University of Zurich for experiments anddata analysis.