Magnetic soft X-ray microscopy: Imaging spin dynamics at the nanoscale

Time-resolved magnetic X-ray microscopy combines in a unique way spatial resolution down to 15 nm with a temporal resolution of less than 100 ps. The former is enabled through state-of-the-art Fresnel zone plates used as X-ray optical elements and the latter is limited by the inherent time structure of current synchrotron radiation X-ray sources. Using a stroboscopic pump and probe scheme spin dynamics in magnetic systems of confined geometries can be imaged with great detail. The magnetization of the elements is excited with fast electronic pulses with a rise time of 100 ps that are launched into waveguide structures. Varying the delay time between the pump and the X-ray probing pulses one can image in real space the temporal evolution of the magnetic configuration in nanoscale elements. This paper is based on an invited talk given at the ICM2006 conference and provides an overview of the current status of time-resolved soft X-ray microscopy. Studies of vortex dynamics in rectangular structures are reported as a specific example