2003/07/23 by D. N. Tsigankov, Dmitry Tsigankov, E. Pazy +3 · 2 citations
Physics and Astronomy · #Quantum and electron transport phenomena #Random lasers and scattering media #Spectroscopy and Quantum Chemical Studies #cond-mat.dis-nn
paper · pdf · doi:10.1103/physrevb.68.184205
25 pages, 8 figures, 1 table
arxiv created 2003/07/23 · openalex publication_date 2003/11/20 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Using numerical simulations we study the long-time relaxation of the hopping conductivity. Even though no modern computation is able to simulate the behavior of a large size system over minutes or hours so as to observe the relaxation, we have been able to show that the long-time relaxation and aging effect observed in experiments can be explained in terms of slow transitions between different pseudo ground states. This was achieved by showing that different pseudoground states may have different conductivities and that the dispersion of conductivities is in agreement with the experimental data. We considered two different two-dimensional models with electron-electron interaction: the lattice model and the random site model, corresponding to ``strong'' and ``weak'' effective disorder. For the lattice model, effectively strong disorder, we have shown that the universality of the Coulomb gap, which is responsible for the universal Efros-Shklovskii law for the conductivity, suppresses the long-time relaxation of conductivity since the universality strongly decreases the dispersion of conductivities of the pseudoground states.