arXiv subjects

P. Weinberger

Publications and source records attributed to P. Weinberger.

21 records · Page 2Linked to original sources

arXiv2000

Numerically improved computational scheme for the optical conductivity tensor in layered systems

The contour integration technique applied to calculate the optical conductivity tensor at finite temperatures in the case of layered systems within the framework of the spin-polarized relativistic screened Korringa-Kohn-Rostoker band structure method is improved from the computational point of view by applying the Gauss-Konrod quadrature for the integrals along the different parts of the contour and by designing a cumulative special points scheme for two-dimensional Brillouin zone integrals corresponding to cubic systems.

cond-mat.mtrl-sci↗

arXiv2000

Electrical transport properties of bulk Ni$_{c}$Fe$_{1-c}$ alloys and related spin-valve systems

Within the Kubo-Greenwood formalism we use the fully relativistic, spin-polarized, screened Korringa-Kohn-Rostoker method together with the coherent-potential approximation for layered systems to calculate the resistivity for the permalloy series Ni$_{c}$Fe$_{1-c}$. We are able to reproduce the variation of the resistivity across the entire series; notably the discontinuous behavior in the vicinity of the structural phase transition from bcc to fcc. The absolute values for the resistivity are within a factor of two of the experimental data. Also the giant magnetoresistance of a series of permalloy-based spin-valve structures is estimated; we are able to reproduce the trends and values observed on prototypical spin-valve structures.

cond-mat.mtrl-sci↗

arXiv2000

A proper ballistic calculation of tunneling conductance for real junctions

Employing an ab initio Screened Korringa-Kohn-Rostoker (SKKR) band structure method for a metal-vacuum-metal junction, we find that the tunnel conductance is different when it is calculated across the barrier and far from it. We attribute this difference to an artefact of the ballistic approach which overestimates the role of specular reflections, and its inability to pick up contributions from localized interface states. To reconcile the ballistic approach with experiment, we propose that the tunnel conductance should be calculated as if it is measured directly across the barrier. In this case the predicted tunneling magnetoresistance is larger.

cond-mat.mes-hall↗