Open AccessCharacteristic of alternating current hopping conductivity in one-dimensional binary disordered system with off-diagonal correlations
Author(s) -
Song Ma,
Hui Xu,
Yanfeng Li,
Penghua Zhang
Publication year - 2007
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.56.5394
Subject(s) - condensed matter physics , conductivity , binary number , diagonal , electrical resistivity and conductivity , delocalized electron , physics , kubo formula , alternating current , thermal conduction , conductance , electric field , uncorrelated , materials science , thermodynamics , quantum mechanics , mathematics , statistics , voltage , geometry , arithmetic
Based on a tight-binding disordered model describing a single electron band, we establish a model of one-dimensional binary disordered systems with off-diagonal correlations, and derive the alternating current (ac) conductance formula. By calculating the ac conductivity, the function of disorder and off-diagonal correlations in electronic transport are analyzed, and the dependence of the ac conductivity on the field frequency and the temperature is studied. The results indicate that the ac conductivity of one-dimensional binary disordered system decreases with the increasing of the degree of lattices energy disorder. And the ac conductivity of the system is also dependent on the probabilities p, which represents the degree of compositional disorder of the system to some extent. The ac conductivity of system first decreases with the increasing of p, then increases with farther increasing of p. We also find that off-diagonal correlations lead to delocalization and enhance the ac conductivity of the systemnamely, the ac conductivity of one-dimensional binary disordered system with off-diagonal correlations is larger than that of uncorrelated system in the Anderson limit. Moreover, the ac conductivity of one-dimensional binary disordered system decreases with the increasing of temperature, and increases drastically with the increasing of the frequency of the electric field.