Nonlinear conductivity of two-dimensional Coulomb glasses

Abstract

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 found that in the nonlinear regime the site occupancy in the Coulomb gap follows a Fermi-Dirac distribution with an effective temperature $T_{\mathrm{eff}}$, higher than the phonon bath temperature $T$. The value of the effective temperature is compatible with that obtained for slow modes from the generalized fluctuation-dissipation theorem. The nonlinear conductivity for a given electric field and $T$ is fairly similar to the linear conductivity at the corresponding $T_{\mathrm{eff}}$. We found that the dissipated power and the effective temperature are related by an expression of the form $(T_{\mathrm{eff}}^{\alpha }-T^{\alpha })T_{\mathrm{eff}}^{\beta -\alpha }$.

9 pages, 9 figures

References in corpus (3)

• Jumps in current-voltage characteristics in disordered films
• Heterogeneous dynamics of the three dimensional Coulomb glass out of equilibrium
• Hot electron effects and non-linear transport in hole doped manganites