A08 Spin+Exchange-Dynamics: Exchange interaction on femtosecond timescales
Prof. Dr. Martin Aeschlimann (Department of Physics, TU Kaiserslautern)
Prof. Dr. Bärbel Rethfeld (Department of Physics, TU Kaiserslautern)
Prof. Dr. Hans Christian Schneider (Department of Physics, TU Kaiserslautern)
New experimental techniques have made it possible to study the dynamics of individual elements in ferromagnetic and ferrimagnetic alloys, uncovering novel non-equilibrium states such as transient ferromagnetic-like states in ferrimagnets. Project A08 investigates the exchange interaction in metallic magnets and hybrid systems at its fundamental timescales. It uses a rather new time-resolved magneto-optical Kerr technique based on high-harmonic generation that allows one to disentangle the role of the exchange interaction from other competing ultrafast processes (such as the exchange of angular momentum with the lattice) in the fs spin dynamics. In close connection with experiment, dynamic simulations of the exchange-coupled spin dynamics in magnetic materials with a high density of electrons will be performed. In particular, the collective electron dynamics and interaction with element-specific core states will be modeled to simulate exchange-coupled alloys of different composition and layered heterostructures with exchange coupling. The theoretical description will be based on material-specific densities of states to provide insight for systems with different sublattices as well as for alloys of imperfect crystalline order.
Aim 1: Development of a microscopic understanding of exchange-coupled spin dynamics on femtosecond timescales in metallic magnetic materials;
Aim 2: Achieve control of the exchange interactions in complex magnetic alloys and hybrid systems.