Past colloquia and seminars


Effects of topology and correlations in real-time spin dynamics

General public Colloquium / Congress / Forum

A single spin exchange coupled to a large conduction-electron system, i.e., the Kondo model, is one of the central paradigms of many-body theory. Here, we study the real-time dynamics of this system by suddenly switching the direction of a magnetic field coupling to the spin. The field polarizes the spin and suppresses Kondo screening. The resulting spin dynamics, precession and damping, is traditionally described by the Landau-Lifschitz-Gilbert equation. Here, we point out some novel and unconventional topological and correlation effects showing up in the dynamics, such as ill-defined Gilbert damping, incomplete spin relaxation and the presence of a geometrical spin torque. It is argued that these effects are important ingredients for a realistic theory of, e.g., nano spintronics devices.

When? 20.02.2019 17:15 - 18:15
Where? PER 08 0.51, bâtiment de Physique
Chemin du Musée 3
1700 Fribourg
speaker Prof. Michael POTTHOFF
Institute for Theoretical Physics
University of Hamburg, Germany
Contact Prof. Philipp Werner
chemin du Musée 3
1700 Fribourg
026 300 91 34