Application of the point-like contact model: Resistance Oscillations of the Domain Wall in Magnetic Nanowires and Junctions due to Mean Free Path Effects

TL;DR

This paper models how electron mean free path effects cause resistance oscillations in magnetic nanowires and junctions with single domain walls, revealing size-dependent quantum scattering phenomena.

Contribution

It introduces a point-like contact model that explains resistance oscillations due to mean free path effects in magnetic nanowires and junctions, covering a wide diameter range.

Findings

Resistance oscillations depend on nanowire diameter and electron scattering conditions.

Oscillations are more pronounced in homogeneous nanowires than segmented ones.

Model aligns with experimental data for single and double domain wall resistances.

Abstract

This work is focused on determining the electrical resistance, which induced by single domain wall in magnetic nanowire with a negligible defect. The provided model covers a wide range of nanowire's diameters. The obtained result demonstrates a few orders rapid reduction of the domain wall resistance accompanied by its possible deviations versus the diameter growth ranging from 1.2 nm to 15.2 nm. The origin of these deviations, which are also identified as oscillations, is referred to the non-uniform electron scattering on the domain wall due to the intermixing electron scattering conditions: ballistic for one spin channel and quasi-ballistic for other one with opposite spin direction. It may happen when the domain wall width by value is approximately in between two lengths: a mean free path with the spin down and spin up. The indirect evidence of this finding is also coming from the fact that homogeneous nanowires shows the most valuable domain wall resistance oscillations by magnitude rather than segmented magnetic nanowires. In addition to the approach, where DW width is constant, the other reasonable model is used when the domain wall can be constrained for some conditions. The same results are valid for magnetic junctions with domain wall. Finally, resistance simulation in the diffusive range, when a diameter of the nanowire (or point-like junction) is larger than any of spin resolved mean free path of electrons, successfully follows experimental data for the single and double domain wall resistances available in literature.