Third Funding Period 2024-2027:
A08 Spin+Exchange Dynamics: Exchange interaction on ultrafast timescales
Prof. Dr. Martin Aeschlimann (Department of Physics, RPTU)
Prof. Dr. Bärbel Rethfeld (Department of Physics, RPTU)
Prof. Dr. Hans Christian Schneider (Department of Physics, RPTU)
Project A08 is concerned with the manipulation of electronic and spin excitations in magnetic materials on the time and length scales of the exchange coupling. Experimentally and theoretically, we will study ultrafast electron dynamics in antiferromagnets (AFM) and altermagnets, motivated by our recent measurement of an optically induced ultrafast demagnetization dynamics in AFMs. Hybrid magnetic systems formed by molecules on surfaces show the potential for chemical interactions to impact exchange-based spin functionalities at interfaces. We will investigate their dynamics far from equilibrium as well as the extension of the optically induced intersite spin transfer (OISTR) to these systems.
Second Funding Period 2020-2023:
A08 Spin+Exchange-Dynamics: Exchange interaction on femtosecond timescales
Prof. Dr. Martin Aeschlimann (Department of Physics, RPTU)
Prof. Dr. Bärbel Rethfeld (Department of Physics, RPTU)
Prof. Dr. Hans Christian Schneider (Department of Physics, RPTU)
Project A08 studies exchange-driven magnetization dynamics on its intrinsic femtosecond timescales in systems with itinerant electrons and/or localized spins. In particular, it investigates metallic alloys, antiferromagnetically coupled systems and hybrid systems, such as spin-carrying molecular complexes on surfaces. It uses an advanced version of the time-resolved magneto-optical Kerr spectroscopy with fs-XUV radiation that allows to study the element-specific magnetization dynamics under ultrahigh vacuum conditions. In close connection with experiment, dynamical simulations of the exchange-coupled spin dynamics in bulk magnetic materials and in hybrid systems are performed.
First Funding Period 2016-2019:
A08 Spin+Exchange-Dynamics: Exchange interaction on femtosecond timescales
Prof. Dr. Martin Aeschlimann (Department of Physics, RPTU)
Prof. Dr. Bärbel Rethfeld (Department of Physics, RPTU)
Prof. Dr. Hans Christian Schneider (Department of Physics, RPTU)
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