Energy and angular momentum exchange between electron and spin-system in ferromagnetic films

点击翻译按钮获取中文摘要

The subject of this project is to study the dynamics of the relevant energy and angular momentum transfer between excited electrons and the spin system of a ferromagnetic solid. These dissipation processes are important for many fundamental mechanisms in the field of ultrafast spin dynamics. Using different laser pulse intensities we will be able to distinguish two different regimes: 1) the direct interaction of a single excited electron and the spin-system. Special emphasis will be given to the strength of spin-waves loss modes, local vs. nonlocal spin-orbit coupling, and the strength of interface momentum take-up. 2) the case of a strong thermal non-equilibrium between a highly excited electron system and a cold spin system. The aim is to gain detailed insight into the response of the magnetization after an ultrafast heating laserpulse. The studies will be performed by femtosecond pump-probe methods: magneto-optic Kerr effect and linear and nonlinear photoemission. The investigations will focus on thin films and multilayers of the itinerant ferromagnets Co, Ni, Fe and of the ferromagnet Gd with a localized spin moment.