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CPA Study of the Electrical Conductivity for Various Percolation Models
Author(s) -
Kolley E.,
Kolley W.,
Fehske H.
Publication year - 1982
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2221090214
Subject(s) - multiplicative function , condensed matter physics , diagonal , lattice (music) , percolation (cognitive psychology) , conductivity , electrical resistivity and conductivity , percolation threshold , square lattice , vertex (graph theory) , physics , electron , statistical physics , tight binding , coherent potential approximation , materials science , quantum mechanics , mathematics , electronic structure , mathematical analysis , combinatorics , neuroscience , graph , geometry , acoustics , ising model , biology
Abstract Transport properties are examined for randomly disordered systems comprising a mixture of conducting and insulating components. The tight‐binding models on a s.c. lattice are specialized to purely diagonal disorder, off‐diagonal disorder of the multiplicative and additive type, also in the presence of electron‐electron interaction; the percolation limits are reached by the breaking of inter‐ or intra‐species links. The effective medium is provided by the CPA (coherent potential approximation) and its extended version ODCPA, if necessary combined with the Hartree‐Fock approximation. The dc conductivity σ vanishes at a critical concentration x c of inaccessible sites at fixed Fermi energy. The ODCPA involving vertex corrections refers to localization in the middle of the band. Numerical σ( x )‐results are presented.