The X-ray view of ultrafastmagnetism

Abstract

Magnetism is a quantum effect at work in the macroscopic world we live in. As such it has fascinated mankind for millennia and also led to many modern-day applications, very prominently in information processing and storage. Polarized soft x-rays have been used for several decades at synchrotron light sources to obtain fascinating new insights into nanoscalemagnetism. The separation of spin and orbital magnetic moments, for instance, enabled detailed insights into the interplay of magnetic interactions at the atomic level. The now available polarized soft x-ray pulses from x-ray free electron lasers with sub-100 femtoseconds duration allow us to observe the magnetic interactions at work in real time. The ultimate goal of such studies is to understand how electron spins may be manipulated by ultrashort magnetic field, spin-polarized current, or light pulses and to observe the fundamental speed limits for nanoscale spin motion.