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Domain walls in ferromagnetic metals are known to be a source of resistance. We have studied the resistance resulting from a onedimensional Néel-type magnetic domain wall in presence of Rashba spin-orbit coupling and external magnetic field. The analysis has been based on Boltzmann transport equation, within the relaxation time approximation. Through this formalism, we have shown that the spin-flip scattering and the resulting resistance originating from the Rashba spin-orbit coupling can be suppressed by the applied external magnetic field.Index Terms-Magnetic domain wall, magnetic field, resistance, spin-orbit interaction.

The influence of phonons on domain wall magnetoresistance in magnetic nanowires has gained crucial importance. In the present work, the resistance of a magnetic domain wall in a magnetic nanowire has been investigated in the presence of a longitudinal acoustic phonon using the semiclassical approach. The analysis has been based on the Boltzmann transport equation, within the relaxation time approximation. The resistance resulting from the one-dimensional Néel-type domain wall has been studied when the modulation of the exchange interaction by lattice vibrations and the electron-phonon interaction are considered. The results indicate that phonons play a significant role in resistance, and increasing the number of phonons leads to enhancement of the domain wall resistance. Increasing and decreasing the domain wall resistance is observed via enhancing the temperature and mass of the domain wall, respectively. The effect of phonons on the resistance of the domain wall is considerable in providing new spintronics devices based on the nanowires at high temperatures.

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Friedel oscillations of the graphene-like materials are investigated theoretically for low and intermediate Fermi energies. Numerical calculations have been performed within the random phase approximation. It was demonstrated that for intra-valley transitions the contribution of the different Dirac points in the wave-number dependent quantities is determined by the orientation of the wave-number in k-space. Therefore, identical contribution of the different Dirac points is not automatically guaranteed by the degeneracy of the Hamiltonian at these points. Meanwhile, it was shown that the contribution of the inter-valley transitions is always anisotropic even when the Dirac points coincide with the Fermi level (EF = 0). This means that the Dirac point approximation based studies could give the correct physics only at long wave length limit. The anisotropy of the static dielectric function reveals different contribution of the each Dirac point. Additionally, the anisotropic k-space dielectric function results in anisotropic Friedel oscillations in graphene-like materials. Increasing the Rashba interaction strength slightly modifies the Friedel oscillations in this family of materials. Anisotropy of the dielectric function in k-space is the clear manifestation of band anisotropy in the graphene-like systems.