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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.
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TL;DR: In this article, it was shown that the coherent potential approximation in the dilute alloy limit based on a simple model density of states leads to a very simple rule of the surface segregation in dilute binary transition metal alloys.
18 citations
TL;DR: In this article, the authors apply the coherent potential approximation to the problem of metal-insulator transitions in the model of Falicov and Kimball (1969), and show that, even after taking into account the changes in the conduction band density of states due to the random distribution of scattering centres as electrons are promoted from localized to itinerant states, depending on the values of the parameters of the model, the following possibilities appear: (a) insulating phase at all temperatures, (b) metallic phase, (c) smooth or first order transitions between these two phases as
Abstract: The authors apply the coherent potential approximation to the problem of metal-insulator transitions in the model of Falicov and Kimball (1969). It is shown that, even after taking into account the changes in the conduction band density of states due to the random distribution of scattering centres as electrons are promoted from localized to itinerant states, depending on the values of the parameters of the model, the following possibilities appear: (a) insulating phase at all temperatures, (b) metallic phase at all temperatures, (c) smooth or (d) first order transitions between these two phases as the temperature increases. The 'excitonic phases' of Ramirez et al (1970) are shown to correspond to the split band regime of the coherent potential approximation.
18 citations
TL;DR: In this paper, the diffusion constant of a particle or an excitation in randomly fluctuating media is studied theoretically and explicit calculation of D has been performed by using the dynamical coherent potential approximation and by computer experiments.
Abstract: Diffusion of a particle or an excitation in randomly fluctuating media is studied theoretically. The model is a tight-binding Hamiltonian whose diagonal or off-diagonal elements are modulated by mutually-independent random noises. The non-white modulation models are investigated precisely. The diffusion constant ( D ) depends on the noise-parameters such as the amplitude ( Δ ) and the correlation time (γ -1 ) and also depends on the static band width ( W ). Explicit calculation of D has been performed by using the dynamical coherent potential approximation and by computer experiments. In the case that diagonal elements are modulated by discrete-jump noises, D as a function of γ has a minimum in the vicinity of \(\hbar\gamma{=}\varDelta\) if Δ ≫ W . On the contrary, D (γ) is a monotonically-increasing function of γ if Δ ≪ W . In the off-diagonal fluctuation case, the diffusion constant exhibits a feature qualitatively different from the diagonal fluctuation model.
18 citations
TL;DR: In this article, Anderson's theory of localization is critically reviewed and extended, with particular emphasis on some controversial aspects, and it is shown that when the randomness exceeds a certain critical value, all the eigenstates become localized in agreement with Anderson's original result.
18 citations
TL;DR: In this article, the authors used the Kubo-Greenwood formula in combination with the fully relativistic spin-polarized screened Korringa-Kohn-Rostoker method and the Coherent Potential Approximation to calculate the residual resistivity and the anisotropic magnetoresistance of bulk Ni-rich alloys.
Abstract: By using the Kubo-Greenwood formula in combination with the fully relativistic spin-polarized Screened Korringa-Kohn-Rostoker method and the Coherent Potential Approximation we calculated the residual resistivity and the anisotropic magnetoresistance of bulk ${\mathrm{Ni}}_{1\ensuremath{-}c}{\mathrm{Fe}}_{c}$ alloys in the Ni-rich regime. While the calculated residual resistivities are typically 30--40% smaller than the measured values, for the anisotropic magnetoresistance ratios we obtained an excellent agreement between theory and experiment. Varying the angle between the directions of the magnetization and of the current we found a functional dependence of the resistivity consistent with the formula proposed originally by D\"oring.
18 citations