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Non‐linear conductivity in Coulomb glasses
Author(s) -
Caravaca M.,
Voje A.,
Bergli J.,
Ortuño M.,
Somoza A.M.
Publication year - 2009
Publication title -
annalen der physik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.009
H-Index - 68
eISSN - 1521-3889
pISSN - 0003-3804
DOI - 10.1002/andp.200910377
Subject(s) - citation , coulomb , computer science , information retrieval , calculus (dental) , library science , physics , medicine , quantum mechanics , dentistry , electron
We have studied the nonlinear conductivity of two‐dimensional Coulomb glasses. We have used a Monte Carlo algorithm to simulate the dynamic of the system under an applied electric field E. We have compared results for two different models: a regular square lattice with only diagonal disorder and a random array of sites with diagonal and off‐diagonal disorder. We have found that for moderate fields the logarithm of the conductivity is proportional to$\sqrt{E}/T^2$ , reproducing experimental results. We have also found that in the nonlinear regime the site occupancy in the Coulomb gap follows a Fermi‐Dirac distribution with an effective temperature T eff higher than the phonon bath temperature T.