Recent research on electron transport through nanocontacts has stimulated great interest in understanding the enhanced magnetoresistance that has been observed. Further interest is generated by the possibility of appications in magnetoelectronic devices. In recent work done in collaboration with scientists at Seagate Research, Pittsburgh, we have investigated the electrical resistance of a constrained domain wall in a nanojunction. The geometry of the nanoconstriction is shown on the right, where the left electrode is a low-anisotropy material (Ni) and the right one has high-anisotropy (CoPt). The calculations show that it is possible to trap the domain wall within the constriction region, and that the domain wall can be compressed by an applied magnetic field resulting in the enhanced domain wall resistance. This implies that the domain wall resistance can be controlled by the applied magnetic field.

E.Y. Tsymbal, S.S. Jaswal, R. Skomski, O.N. Mryasov, and R.W. Chantrell