Dresden 2003 – wissenschaftliches Programm
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MA: Magnetismus
MA 14: Poster: Schichten(1-31), Spinabh.Trsp.(32-47), Exch.Bias(48-54), Spindyn.(55-64), Mikromag.(65-76), Partikel(77-88), Oflmag.(89-92), Spinelektr.(93-98), Elektr.Theo.(99-103), Mikromag+PhasÜ+Aniso.(104-122), MagnMat.(123-134), Messm+Mol-Mag.(135-139), Kondo(140-151)
MA 14.42: Poster
Dienstag, 25. März 2003, 15:15–19:15, Zelt
Scattering of electrons from domain walls in ferromagnets — •Vitalii Dugaev1, Jamal Berakdar1, and Jozef Barnas2 — 1Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle — 2Department of Physics, Adam Mickiewicz University, 61-614 Poznan, Poland
We present a theoretical model for the calculation of the resistance due to domain wall scattering in ferromagnetic systems. The limiting cases of thick (smooth) and thin (sharp) domain walls is considered in detail. In the former case the calculations have been performed in the semiclassical approximation. The question of possible accumulation of spin and charge at the domain wall is addressed. The additional resistance due to the domain wall is rather small in this regime. However, it can be either positive or negative, which depends on the specific material parameters. In the case of sharp domain walls, the spin-flip scattering enhances the probability of electron reflection from the wall for each spin channel. Detailed calculations have been performed for quantum wires and in the limit where the domain wall thickness is significantly smaller than the electron Fermi wavelength. The additional resistance is then positive and can be relatively large. Since the electron-electron interaction can play a significant role in quasi-one dimensional systems, we investigated the influence of this interaction on the domain wall resistance. The results of the present model indicate a large magnetoresistance in magnetic microjunctions. They also show that the spin-flip reflection from the domain wall and electron-electron interactions can be responsible for the enhancement of the magnetoresistance.