Coherent potential approximation

About: Coherent potential approximation is a research topic. Over the lifetime, 1930 publications have been published within this topic receiving 36805 citations.

Scattering of electromagnetic waves by nearly periodic structures

Abstract: We present a method, based on the coherent potential approximation, for the treatment of disorder in photonic crystals. We apply the method to the study of light absorption by a three-dimensional array of plasma spheres distributed randomly in a host dielectric medium. We find that the effect of disorder on the absorbance of a thick slab of the material consisting of many layers of spheres is much less pronounced than in the corresponding case of a single layer of spheres.

Spin-disorder resistivity of ferromagnetic metals from first principles: The disordered-local-moment approach

Abstract: The paramagnetic spin-disorder resistivity (SDR) of transition-metal ferromagnets Fe, Co, Ni, ordered transition metal alloys Ni${}_{3}$Mn and Fe${}_{3}$Si as well as Ni${}_{2}$Mn$X$ ($X=\text{In}$,Sn,Sb) Heusler alloys is determined from first principles. SDR is evaluated similar to the residual resistivity by using the disordered local moment (DLM) model combined with the Kubo-Greenwood linear response calculation. The electronic structure is determined within the tight-binding linear muffin-tin orbital method and the coherent potential approximation (CPA) applied to the DLM state. We also estimate the temperature dependence of the resistivity below the Curie temperature using a simple model. The results agree well with the supercell Landauer-B\"uttiker calculations and, generally, with experimental data. For the Ni${}_{2}$MnSb Heusler alloy it is necessary to include substitutional disorder of B2-type to explain the experimental data.

Spin density in real and momentum space in multi-atom alloys by kkr-cpa method

Abstract: The application of the spin-polarized version of multiple scattering the- ory for obtaining electron charge and spin densities in both real and momen- tum spaces of concentrated, multi-atom disordered alloys is presented. This method is based on the Korringa—Kohn—Rostoker (KKR) band structure ap- proach and coherent potential approximation (CPA) method. The effective one-electron potential is constructed within local spin density approxima- tion. The magnetic neutron form factors are in real space of our main inter- est. With the recent developments of new synchrotron photon sources, the Compton profile becomes the most interesting target in momentum space. In the most of examples, spin momentum density and its specific structure due � to Fermi surface will be shown. To get accurate enough description in mo- mentum space and quantity like Compton profile, the determination of the Fermi surface must be done with high precision. In this context we show how to apply generalized Lloyd formula for accurate determination of the Fermi level. Also we show how to use efficiently complex energy integration method for the computation of matrix elements, G(τ, τ) or G(p, p), of the KKR—CPA Green . function. Results for the iron—silicon ferromagnetic binary alloys and half-metallic ferromagnetic Heusler alloys are presented. PACS numbers: 71.15.Cr, 71.18.+y, 78.90.+t

Galvanomagnetic Effects in Alloys in Quantizing Magnetic Fields

Abstract: The one-electron version of the Kubo formula is used to derive the components of the conductivity tensor for a simple model of a binary alloy characterized by the parabolic dispersion law and the zero range of potentials of scatterers. The configurational averaging is performed using the coherent potential approximation and therefore the final formulae apply for a broad range of alloy parameters. They are shown to yield proper high field and low field limits and to agree, for appropriate values of parameters, with the quasi-classical approximation. [Russian Text Ignored].