TRR 360 Sonderseminar:

Probing ultrafast Electron and Spin Dynamics in Momentum, Space, and Time

Martin Aeschlimann

Probing ultrafast Electron and Spin Dynamics in Momentum, Space, and Time

Prof. Dr. Martin Aeschlimann

Department of Physics and Research Center OPTIMAS, RPTU Kaiserslautern-Landau

Competing interactions of spin with charge and lattice, determined by the spin-orbit interaction, give rise to rich phase diagrams of states in novel correlated electron materials. In such materials, magnetically ordered phases are very often in direct competition with other ordered phases, such as a spin- or charge-ordered phase. Unfortunately, the dominant interaction responsible for the formation of a particular phase is often difficult to determine at thermal equilibrium, so that a fundamental understanding of the underlying competing interactions is out of reach using static measurements. Time-resolved spectroscopy techniques have the potential to overcome these limitations by temporally driving the material system out of equilibrium. The subsequent relaxation pathways are then determined by the spin-charge lattice interactions, which can be studied using different photoemission techniques. In this talk I will show how recent developments in ultrafast light sources and photoemission detector technology have paved the way for a completely new generation of time- and spin-resolved photoemission experiments. With this tool at hand we can directly observe the temporal evolution of excited carriers and spins in energy, momentum space and time, providing an unprecedented insight into the fundamental energy and (angular) momentum dissipation mechanisms even in complex condensed matter.