There one can find some article realted to Swerts diplom work.
In this article, we discuss a system that is appropriately called a domain-wall junction (DWJ). The DWJ is a close analog of the Josephson junction with respect to the usefulness of both systems in studying switching by thermal activation (TA) and by quantum tunneling (QT). We will show through theoretical analysis that it is within our means to fabricate a DWJ that should exhibit switching via quantum tunneling of magnetization. We further lay out experimental procedures for looking for quantum tunneling of magnetization in a DWJ; these procedures are based upon those used in observing macroscopic quantum tunneling in Josephson junctions. Two examples of DWJ's have been recently made that apparently show a crossover from TA to QT.
A GdFe/TbFe/GdFe trilayer constitutes a magnetic nanostructure: the domain wall junction. With this device, we studied the propagation of 180° domain walls from one GdFe layer to the other, through a single planar defect (the thin TbFe layer) that acts as an artificial energy barrier. Before crossing the energy barrier, by thermal activation, due to the applied magnetic field, the domain walls are compressed against the TbFe layer. Nucleation, compression, and propagation phenomena of 180° domain walls are presented. The behavior of domain walls is followed from the electrical resistivity of the sample. A parallel between the domain-wall decompression and the exchange biasing problem in ferromagnetic/antiferromagnetic bilayers is proposed.
The motion of a magnetic domain wall in a submicrometer magnetic wire was detected by use of the giant magnetoresistance effect. Magnetization reversal in a submicrometer magnetic wire takes place by the propagation of a magnetic domain wall, which can be treated as a "particle." The propagation velocity of the magnetic domain wall was determined as a function of the applied magnetic field.