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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 authors applied coherent potential approximation to the optical conductivity of substitutionally disordered off-diagonal binary alloys with the BCC host lattice, and found that anomalous behaviour of the opticalconductivity is observed in cases where the Fermi level of the system lies in the minimum of the DC conductivity.
Abstract: The coherent potential approximation is applied to a study of the AC electrical conductivity of substitutionally disordered off-diagonal binary alloys with the BCC host lattice. The validity of the concept of the optical relaxation time for intraband transitions is discussed. It is found that anomalous behaviour of the optical conductivity is observed in cases where the Fermi level of the system lies in the minimum of the DC conductivity.
TL;DR: In this article, the critical percolation density for temperature-dependent site percolations was calculated by using the lattice-gas model of atoms, especially inside the region where the sublattice ordering occurs (repulsive interaction) or liquid and gas phases coexist (attractive interaction).
Abstract: Critical percolation density for temperature-dependent site percolation problem is calculated by using the lattice-gas model of atoms, especially inside the region where the sublattice ordering occurs (repulsive interaction) or liquid and gas phases coexist (attractive interaction). The square lattice is regarded as a resistor network. Any bond in the lattice is conductive or insulating whether both ends of the bond are occupied with atoms or not. The distribution of atoms is determined within the pair approximation from the lattice-gas Hamiltonian with nearest-neighbor interactions. Moreover a single-site effective-medium approximation which is similar to coherent potential approximation is used to obtain the critical percolation density.
TL;DR: The generalized cluster expansion of the coherent potential approximation as applied to the case of a disordered binary alloy is discussed and extended to include the random off-diagonal elements of the Hamiltonian.
TL;DR: In this article, the electron correlation effect in impurity doped semiconductors with use of alloy type model Hamiltonian was investigated and the formation of localized moment and the consequent structures on the density of states corresponding to the impurity band, D - band and host conduction band were studied in the Hartree-Fock approximation and coherent potential approximation.
Abstract: The electron correlation effect in impurity doped semiconductors is investigated with use of alloy type model Hamiltonian. The formation of localized moment and the consequent structures on the density of states corresponding to the impurity band, D - band and host conduction band is studied in the Hartree-Fock approximation and coherent potential approximation. It is shown that the electron correlation effect is emphasized on impurity sites and the metal-insulator transition occurs at the critical impurity concentration induced by the formation of localized moment. Further the effect of valley degeneracy in the case of many valley semiconductors is examined and pointed out to be important on the manner of formation of localized moment in concentrations near the metal-insulator transition.
TL;DR: In this paper, the application of multiple scattering theory to the calculation of the residual resistivity of disordered alloys is discussed, and the linearized KKR is used to evaluate the Kubo formula for several large configurations of atoms.
Abstract: The list of physical properties which are important in the design of materials and which are routinely calculated from first principles within the local density approximation to density functional theory is continually growing. In this paper we discuss the application of multiple scattering theory to the calculation of the residual resistivity of disordered alloys. Progress has been made on two fronts. First, the coherent potential approximation for the sensitivity, which sums to all orders a limited set of multiple scattering diagrams, has given resistivities in agreement with experiment for alloys where the site occupation is roughly random. Second, the linearized KKR was used to evaluate the Kubo formula for several large configurations of atoms and obtain the resistivity with all multiple scattering paths included. This method is not limited to random alloys, but can be applied to short range ordered and amorphous alloys provided the resistivity is high enough to limit the mean free path to a single unit cell.