The TRR 227 kindly invites you to the Theory Colloquium of Martin-Luther-Universität Halle.
Speaker: Prof. Dr. Gustavo Pastor - Theoretical Physics I -
Theory of low-dimensional and nanostructured materials, Universität Kassel
Title: Electronic many-body theory of the laser-induced ultrafast demagnetization of ferromagnetic transition-metals
The ultrafast demagnetization dynamics of itinerant ferromagnets is theoretically investigated in the framework of a many-body pd-band Hamiltonian including hybridizations, Coulomb interactions, spin-orbit interactions and the coupling to the laser field. The time evolution during and after the pulse absorption is determined exactly by performing numerical Lanczos propagations on a small cluster model. The interplay between local spin-orbit interactions and interatomic hopping is shown to be at the origin of the observed postexcitation breakdown of FM correlations between highly stable local magnetic moments. The ultrafast demagnetization effect thus emerges as a robust universal phenomenon reflecting the intrinsic dynamics of the metallic 3d valence electrons. A fruitful connection is thereby established between the nonadiabatic quantum dynamics and the well-known equilibrium statistical mechanics of itinerant-electron ferromagnets.
May 08, 2019 | 04:00 PM c.t.
SR1.02 - Von-Seckendorff-Platz 1
Martin-Luther-Universität Halle-Wittenberg, 06120 Halle