Premium
Generalization of the Effective‐Medium Approximation for Hopping Transport in Amorphous Materials
Author(s) -
Ganter C.,
Schirmacher W.
Publication year - 2000
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/(sici)1521-3951(200003)218:1<71::aid-pssb71>3.0.co;2-m
Subject(s) - generalization , autocorrelation , semiconductor , condensed matter physics , amorphous solid , conductivity , impurity , amorphous semiconductors , algebraic number , function (biology) , variable range hopping , physics , materials science , statistical physics , mathematics , quantum mechanics , mathematical analysis , chemistry , thin film , statistics , organic chemistry , evolutionary biology , biology
Abstract We present a new version of the effective‐medium approximation (EMA) for hopping in structurally disordered systems such as amorphous semiconductors or impurity‐bands of crystalline semiconductors. In contrast to previous theories we are able to include the influence of closed loops in the path summation. These terms are responsible for the algebraic long‐time tails of the velocity autocorrelation function which also show up as non‐analytic terms in the low‐frequency part of the AC conductivity. If the closed‐loop contributions are neglected, the two‐site EMA of Gochanour et al. and Movaghar et al. is re‐obtained. We have tested the results of the present theory against simulations for an r ‐hopping network.