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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 paper, a formulation of the Korringa-Kohn-Rostoker coherent potential approximation (KKPt-CPA) for the treatment of substitutionally disordered alloys within the KKR atomic-sphere approximation (ASA) was presented.
Abstract: We present a formulation of the Korringa-Kohn-Rostoker coherent potential approximation (KKPt-CPA) for the treatment of substitutionally disordered alloys within the KKR atomic-sphere approximation (ASA). This KKR-ASA-CPA represents the first step toward the implementation of a full cell potential CPA, and combines the accuracy of the KKR-CPA method with the flexibility of treating complex crystal structures. The accuracy of this approach has been tested by comparing the self-consistent-field (SCF) KKR-ASA-CPA calculations of Cu-Pd alloys with experimental results and previous SCF-KKR-CPA calculations.
TL;DR: In this paper, the authors developed the dynamical coherent potential approximation (CPA) to the correlated electron system on the basis of the functional integral method and the harmonic approximation, which becomes exact in the high temperature limit, reproduces the results of the second order perturbation theory for small Coulomb interaction, and takes into account the terms to describe the strong correlation limit.
Abstract: We have developed the dynamical coherent potential approximation (CPA) to the correlated electron system on the basis of the functional integral method and the harmonic approximation. The theory becomes exact in the high temperature limit, reproduces the results of the second order perturbation theory for small Coulomb interaction, and takes into account the terms to describe the strong correlation limit. The numerical calculations show that the theory describes the Curie-Weiss susceptibility, a large reduction of the Curie temperature due to the dynamical effects, and a many-body satellite peak as well as a band narrowing in the density of states.
TL;DR: In this article, a 1D binary random alloy model with interactions decaying as 1 r 2, for which the coherent potential approximation (CPA) equations can be obtained in closed form.
TL;DR: Ruban et al. as mentioned in this paper used the generalized perturbation method (GPM) to determine both effective chemical interactions and magnetic exchange interaction parameters of the classical Heisenberg Hamiltonian in disordered alloys.
TL;DR: In this paper, the authors analyzed the competition between high-temperature superconductivity and antiferromagnetism (AF) using the extended Hubbard model containing following matrix elements in the Hamiltonian: Hund's on-site field FH, single-site Coulomb repulsion, two-site charge-charge, exchange, pair exchange and assisted hopping interactions.
Abstract: We analyze the competition between high-temperature superconductivity (SC) and antiferromagnetism (AF) using the extended Hubbard model containing following matrix elements in the Hamiltonian: Hund's on-site field FH, single-site Coulomb repulsion U = ( i , i | 1 / r | i , i ) , two-site charge–charge, exchange, pair exchange and assisted hopping interactions V = ( i , j | 1 / r | i , j ) , J = ( i , j | 1 / r | j , i ) , J ′ = ( i , i | 1 / r | j , j ) , Δ t = ( i , i | 1 / r | j , i ) . In our model, we introduce the possibility of AF ordering by dividing the crystal lattice into two interpenetrating sub-lattices α , β . We use Hartree–Fock (H–F) approximation for all interactions except the strong on-site Coulomb repulsion. The self-energies Σ γ σ ( e ) ( γ = α , β ) are calculated within the coherent potential approximation (CPA). To obtain the SC transition temperature TC and the Neel's temperature TN we solve the coupled equations of motion for the Green's functions. We present numerical results. They show that the AF at half-filling destroys the superconductivity of the s0-wave symmetry. Increase of the Coulomb repulsion in the CPA causes increasing dumping of s0-wave SC, shifts it away from the half-filling point, enhances SC temperature for sub-lattice magnetic moments; 0