Avbildning av magnetiska nanostrukturer med hög spatial och temporal upplösning
Tidsperiod: 2013-01-01 till 2015-12-31
Projektledare: Ronny Knut
Budget: 3 150 000 SEK
Lasers which provide pulse lengths in the order of femtoseconds are today used for magnetically sensitive microscopy that provides high temporal resolution but where the spatial resolution is restricted by the long wavelength of the laser light. A scheme to up-convert the laser light into the extreme-ultraviolet (XUV) regime with short wavelength has recently been realized and is denoted as higher harmonic generation (HHG). We propose an experiment which uses HHG to image the dynamics of magnetic nanostructures with unprecedented combination of spatial and temporal resolution. The method is based on diffractive imaging to avoid the difficulties involved with XUV optics. The study of dynamics in magnetic nanostructures is very important for the development of information storage, processing and communication which today is restricted to indirect experimental methods and simulations. The time resolved diffractive imaging using XUV light opens up the possibility to study several important questions in magntodynamics where we have chosen to study the wave vector dependence of the damping parameter for spin waves. Theory proclaims that the wave vector dependence of the damping parameter, which controls the lifetime and therefore the performance of spin wave based devices, changes for very small wavelengths. This fact has profound implications for device performance and design but has not yet been experimentally confirmed due to limitations in available methods.