A tight-binding model for charge transport in silicate layers

Abstract

Observations and experiments in silicates of the mica group show the transport of electric charge along the cation layers in absence of an electric field, a phenomenon called hyperconductivity. The transport of charge is achieved when a nonlinear vibration brings about that the ions become close enough for the transfer of an electron or hole. A model is developed in detail, approximations of different order for smaller vibration are considered so as to obtain approximate solutions. The full equations are integrated numerically with several approaches to overcome the problem caused by the different time scales of ion and electron movements. Localized solution showing the transport of charge coupled to nonlinear excitations are observed and described.