Uni-Logo Koordinatoren des Kolloquiums:
Prof. Dr. F. Schmidt-Kaler
Institut für Physik
Johannes Gutenberg-Universität
Prof. Dr. Hartmut Wittig
Institut fuer Kernphysik,
Johannes Gutenberg-Universitaet

Physikalisches Kolloquium Mainz

Institut für Kernphysik, Johann Joachim Becher Weg 45

Dienstag, den 04.12.2018 um 16 Uhr c.t. im HS KPH
Tee ab 15:45 Uhr

The Ultrafast Einstein-de Haas Effect

Prof. Dr. Steven Johnson, ETH Zürich Institute for Quantum Electronics

The original experiments showing what is now called the Einstein-de Haas effect were a critical demonstration in early modern physics of the equivalence of angular momentum in electronic spins and mechanical angular momentum. Here I discuss a recent experiment where we investigate using femtosecond x-ray diffraction the dynamics of the Einstein-de Haas effect on picosecond time scales, along the way showing definitively that the long-studied but poorly understood phenomenon of “ultrafast demagetisation” in ferromagnetic iron involves a sub-picosecond time scale transfer of angular momentum from the spin system to the lattice.

Kontakt: Andrea Graham, andrea.graham@uni-mainz.de