Ultrafast dynamics in functional materials

Olof “Charlie” Karis, Molecular and Condensed Matter Physics, was granted 3.3 million SEK for the project “Ultrafast dynamics in functional materials” from the Swedish Research Council for the period 2016-2020.

Project description

Dynamics at ps and shorter timescales are among the most exciting areas of research today. This proposal deals with dynamic properties, e.g. spin waves (magnons), in magnetic materials relevant for many applications of modern magnetism. Synchrotrons have been at the forefront of such studies, as the pulsed structure provides a “strobe light” to illuminate motion on the sub-ns level. By combining synchrotron techniques like X-ray magnetic circular dichroism (XMCD) with ferromagnetic resonance (FMR), we can disentangle the dynamics of complex magnetic material. Our team pioneered this methodology. However, as many synchrotron storage rings moves towards ultra-low emittance, time resolved measurements at such facilities will become increasingly challenging and novel detection schemes will have to be adapted to provide sufficient time resolution to study ultrafast magnetization dynamics. This proposal also has a strong focus on using laser-based overtone sources in the extreme ultraviolet – soft x-ray regime to investigate sub-ps ultrafast dynamics in magnetic systems. We will resolve some of the outstanding controversies in the description of recent experimental findings and arrive at a deeper understanding of the demagnetization process following intense ultra-short excitation. In a greater context, other scientific programs will benefit from the method development that will follow from our proposal.