The Institute of Optics

Studying ultrafast magnetization dynamics with ultrafast extreme ultraviolet light

Emrah Turgut, University of Colorado-Boulder

Goergen 108

Abstract:
Femtomagnetism describes the manipulation of magnetic order on ultrafast (femtosecond) timescales by ultrashort laser pulses. Over the last few decades it has become a challenging research topic of increasing interest, because of its importance for uncovering fundamental phenomena in far-from equilibrium conditions. In this talk, I show that tabletop extreme-ultraviolet radiation sources based on the frequency up-conversion of intense laser light (high-harmonic generation) are ideal probes of ultrafast magnetization dynamics. In particular, these sources produce broadband, coherent, short-wavelength beams with femtosecond-to-attosecond pulse duration. Moreover, we can add simultaneous elementspecific access to multiple atomic species and full-control of polarization to their advantages. These unique experimental capabilities have allowed us to capture the fastest charge and spin dynamics in complex magnetic alloys and multilayer systems, which are also relevant for technological applications. Our recent investigations consolidate our understanding about the role of non-local superdiffusive spin-currents and local spin scattering mechanisms, modifications of the electronic structure in the far-from-equilibrium state, and the angular momentum transfer from the spin system into the lattice after an ultrafast laser excitation.