High-resolution resonant inelastic X-ray scattering with soft X-rays at the ADRESS beamline of the Swiss light source: Instrumental developments and scientific highlights

Abstract The experimental development of the resonant inelastic X-ray scattering (RIXS) technique in the soft X-ray energy range has been tremendous during the last years. The ADRESS beamline at the Paul Scherrer Institut in Switzerland and its RIXS spectrometer SAXES has boosted the scientific capabilities with soft X-ray RIXS. Increased resolving power above 10,000 and the possibility to rotate the spectrometer to different scattering geometries allows analyzing the collective behavior of charge, orbital and spin excitations by assessing their momentum dependence. Focus of most projects at this facility lies in the investigation of low- and medium-energy excitations in correlated electron materials. In addition ADRESS has also been used for RIXS investigations on molecules in the liquid and gaseous phase. This review reports on the recent extension of the optics of the SAXES RIXS spectrometer with an additional grating optimized for the spectral range from ca. 400 to 700 eV. Furthermore, the scientific opportunities emerging from ADRESS are highlighted in RIXS studies on quasi one-dimensional cuprates, oxide heterostructures and a weakly correlated broad band material.