A07 Spin+Exchange: Theory for dynamics of spin and exchange
Dr. Georg Lefkidis (Department of Physics, TU Kaiserslautern)
In project A07 state-of-the-art quantum chemistry calculations will be used in order to investigate the role of the fundamental spin-spin exchange coupling in magnetic molecules, which dominates and controls phenomena such as magneto-optical excitation spectra and magnetic switching. Thus the theory will allow for the targeted design of molecular magnets with desired magnetic properties and potential for controlled spin dynamics, which are of high interest for future nano-spintronic devices. The challenges are to understand the exact nature of the exchange coupling in real magnetic molecules (both isolated and deposited on surfaces), to study static (e.g., magnetic order, spin localization) and dynamic (e.g., spin relaxation) exchange-related phenomena, and to connect those to local (onsite) and/or global (charge-transfer) electronic excitations.
Aim 1: Theory: Derivation of a first-principles theory to project non-localized, many-body, microscopic spin-exchange interaction of strongly correlated magnetic molecules on localized macroscopic intra- and interatomic interactions both statically and dynamically;
Aim 2: Applications: Calculation of phenomenological, macroscopic exchange parameters for real magnetic materials and structures, by calculating the collective behavior of the electrons within the above many-body formalism and studying the spin dynamics of magnetic molecular systems as a function of these parameters.