Workgroup Kuch

Department of Physics
Institute for Experimental Physics

The workgroup of Prof. W. Kuch investigates ultrathin magnetic films, surfaces, adsorbed molecules, and nanostructures that may become relevant in a future spin-based electronics. We use lab-based techniques as well as x-ray spectroscopy using synchrotron radiation, for example at the Berlin synchrotron radiation source BESSY II. Samples are mainly prepared under ultra-high vacuum conditions, using Ar ion bombardment and annealing or in-situ cleaving for substrate preparation, and thermal evaporation of metals or molecules for the deposition of the samples. Thin films or molecular adsorbates are characterized by low- or medium-energy electron diffraction, Auger electron spectroscopy, and x-ray photoelectron spectroscopy. We use magneto-optical Kerr effect and magnetic dichroisms in x-ray absorption spectroscopy and microscopy to measure the magnetic properties. We furthermore dispose of equipment for room-temperature scanning tunneling microscopy, differential reflectance spectroscopy, and ferromagnetic resonance.

We aim at the fundamental investigation of new functional properties in nanoscopic magnetic systems such as molecules adsorbed on solid surfaces or ultrathin films including multilayers, surfaces, and patterned structures. Emphasis is put on the dynamic behavior of such systems at ultrashort time scales. Here our interest is in the interaction between layers with different spin structure, for example ferromagnetic/antiferromagnetic, during the ultrafast optical demagnetization, on all-optical magnetic switching, and on laser-induced magnetic domain-wall motion. Another line of research concerns the investigation of interactions in adsorbed molecular magnetic structures. Examples here are adsorbed spin-crossover molecules or surface-supported two-dimensional metal-organic structures at surfaces. We are also interested in novel two-dimensional systems such as transition metal dichalcogenides with magnetic properties.