First-principles modeling of atomistic magnetization dynamics – from magnons to topological magnets

December 7 2016
Types d’événements
Séminaire SPEC
Anders Bergman
SPEC Salle Itzykson, Bât.774
07/12/2016
from 11:15 to 12:15

Recent experimental findings have highlighted several examples on how a reduced dimensionality and broken symmetries can give rise to unexpected and potentially useful changes in the dynamic response of magnetic materials. Among the prominent examples are the measured excitation spectra of a single monolayer ferromagnet and the emergence of large anti-symmetric, Dzyaloshinskii-Moriya, exchange interactions (DMI) which in turn can give rise to chiral magnetism and topologically non-trivial magnetic structures such as skyrmions.

In this talk we will show how the combination of first-principles calculations and Landau-Lifshitz-Gilbert simulations can be a powerful theoretical tool for studying the magnetization dynamics of nanomagnetic systems. We will present how the dispersion relations for magnetic excitations, including thermal effects, can be simulated. Furthermore we will also show how topological defects in FeGe films and in Co-based multilayers can move in the presence of thermal fluctuations or when driven by electrical currents.

Department of Physics and Astronomy, Materials Theory, Sweden