Chen, Hui-YuanVersteeg, Rolf BaldwinMankowsky, RomanPuppin, MicheleDiniz Leroy, Ludmila MariaSander, MathiasDeng, YunpeiOggenfuss, Roland AlexanderZamofing, ThierryBoehler, PirminPradervand, ClaudeMozzanica, AldoVetter, SeraphinSmolentsev, GrigoryKerkhoff, LindaLemke, Henrik T.Chergui, MajedMancini, Giulia F.2024-04-172024-04-172024-04-172024-03-0110.1063/4.0000236https://infoscience.epfl.ch/handle/20.500.14299/207372WOS:001197533500001We present a new setup for resonant inelastic hard x-ray scattering at the Bernina beamline of SwissFEL with energy, momentum, and temporal resolution. The compact R = 0.5 m Johann-type spectrometer can be equipped with up to three crystal analyzers and allows efficient collection of RIXS spectra. Optical pumping for time-resolved studies can be realized with a broad span of optical wavelengths. We demonstrate the performance of the setup at an overall similar to 180 meV resolution in a study of ground-state and photoexcited (at 400 nm) honeycomb 5d iridate alpha-Li2IrO3. Steady-state RIXS spectra at the iridium L-3-edge (11.214 keV) have been collected and are in very good agreement with data collected at synchrotrons. The time-resolved RIXS transients exhibit changes in the energy loss region <2 eV, whose features mostly result from the hopping nature of 5d electrons in the honeycomb lattice. These changes are ascribed to modulations of the Ir-to-Ir inter-site transition scattering efficiency, which we associate to a transient screening of the on-site Coulomb interaction. (c) 2024 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/)Physical SciencesDynamicsExcitationsElectronPhysicsEnergyStatestext::journal::journal article::research article