Ultrafast Characterization of Structural and Spin Dynamics

This project aims at creating, exploring, and understanding novel metastable and transient states of quantum matter.

The strong coupling of the atomic lattice with charge, spin and orbital degrees of freedom allow quantum materials to exhibit a plethora of exotic phases.

Short electron and light pulses have in the past successfully been used to probe such systems, but only recently have they emerged as a prime tool for driving quantum materials into new states with analogue in equilibrium systems.

We will employ efficient techniques to perturb the lattice, electrons, or spin structures, by means of precisely tuned optical excitations shaped as transient optical gratings.

The project will have extensive access to unique available tools for ultrafast electron microscopy (UEM) and free electron laser-based time and angular resolved photoemission spectroscopy combined with time resolved x-ray photoelectron diffraction.

The ultrafast reversable topological transition in WTe2 will be of special interest and we will study phonon dynamics through diffuse scattering.

In addition we will also focus on optical control of magnetization and laser driven spin dynamics as probed by UEM in Lorentz mode.

We will image of spin wave propagation as well study of the influence of photo driven spin currents on the ultrafast magnetization dynamics.