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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, the effects of local impurity configurations are considered by embedding a large cluster into the effective medium calculated by the Korringa-Kohn-Rostoker coherent potential approximation (KKR-CPA) method.
Abstract: We calculate effective exchange interactions in dilute magnetic semiconductors by taking local environment effects into account. The effects of local impurity configurations are considered by embedding a large cluster into the effective medium calculated by the Korringa-Kohn-Rostoker coherent potential approximation (KKR-CPA) method. Calculated exchange interactions by our cluster embedding method differ from those calculated by the Liechtenstein's method, because in our method the multiple scattering effect between site i and j is fully included. It is also found that the calculated exchange interactions strongly depend on the position of the impurities in the cluster other than site i and j. The average of the configuration dependent interactions approximately converge to the two impurity embedding results. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
4 citations
TL;DR: In this article, a spin-1/2 description of valence holes and Kondo coupling between local spins and carriers, GaAs-based III-V diluted magnetic semiconductors (DMS) are studied in the coherent potential approximation (CPA).
Abstract: Using a spin-1/2 description of valence holes and Kondo coupling between local spins and carriers, GaAs-based III–V diluted magnetic semiconductors (DMS) are studied in the coherent potential approximation (CPA). Our calculated relation between ground-state energy and impurity magnetization shows that ferromagnetism is always favourable at low temperatures. For very weak Kondo coupling, the density of states (DOS) of the host semiconductor is not modified much. Impurity bands can be generated at the bottom of the host band only when Kondo coupling is strong enough. Using Weiss molecular theory, we predict a linear relation of Curie temperature with respect to Kondo coupling and doping concentration x if the hole density is proportional to x.
4 citations
TL;DR: In this article, the local coherent potential in the frame of multiple scattering theory was applied to calculate the electron structure of nonstoichiometric carbides, and the muffin-tin aproximation of the crystalline potential was used.
4 citations
TL;DR: The electronic structure and ground state parameters of B2 RuAl-based refractory alloys have been investigated in the framework of the density functional theory using the exact muffin-tin orbital m... as discussed by the authors.
Abstract: The electronic structure and ground state parameters of B2 RuAl-based refractory alloys have been investigated in the framework of the density functional theory using the exact muffin-tin orbital m ...
4 citations
TL;DR: In this paper, the authors measured the Raman spectra of boron-doped single-crystalline diamond at excitation wavelengths between 3640 and 10640 nm and found that the first-order Raman band at 1332 cm-1 shifts to the low-frequency side, broadens, and develops a derivative-like lineshape as the BORON concentration increases.
Abstract: The Raman spectra of boron-doped single-crystalline diamond were measured at excitation wavelengths between 3640 and 10640 nm and found that the first-order Raman band at 1332 cm-1 shifts to the low-frequency side, broadens, and develops a derivative-like lineshape as the boron concentration increases The derivative-like lineshape can be explained by Fano interference Furthermore, I found that the asymmetric lineshape changes between excitation wavelengths of 5145 and 7850 nm From a comparison of the normalized relative Raman intensity as a function of the excitation energy and the density of states (DOS) in the valence band in the B-doped diamond calculated previously by the coherent potential approximation, the abnormal change in the Raman lineshape is attributed to a change in the DOS in the valence band at approximately 20 eV Raman spectroscopy provides us with extensive information on carrier concentrations, and electronic band structures of B-doped diamond
4 citations