Ultrafast dynamics and transient states

Methods and Instrumentation for Synchrotron Radiation Research: Quantum condensed matter: magnetism, superconductivity and beyond

For quantum materials, driven and transient states are central towards the ultrafast control of phase transitions, smaller systems and faster time scales. Controlling phase transitions on ultrafast time scales is our prime goal within “Ultrafast dynamics, driven, and transient states”. Mode selective excitation through resonant pumping permits to prepare a well-defined excited state and to probe its evolution on ultrafast time scales. Here, the interplay between different structural and electronic degrees of freedom will be determined and used to control the phase transition. We have pioneered ultrafast dynamics especially at our FEMTOSPEX slicing facility at BESSY II, the Linac Coherent Light Source (LCLS) at Stanford and FLASH at DESY. These projects will benefit strongly from the flexible pulse length that the BESSY VSR upgrade provides. Beyond time-resolved magnetic absorption and elastic scattering at FEMTOSPEX and BESSY VSR, new instrumentation will reveal the interrelation between electronic and structural order, low-energy excitations and macroscopic properties base on momentum and energy transfer resonant inelastic X-ray scattering (METRIXS) at BESSY II combined with time resolved RIXS at the Heisenberg limit in the hRIXS Helmholtz International Users consortium at XFEL. We are strongly associated with Milestone MAG.5: “Identify a transient state in a driven phase transition of a functional material.”