Thermal solitons and solectrons in nonlinear conducting chains

Abstract

We present a model for nonlinear excitations in bio(macro)-molecules stable at room temperature and offering a possible mechanism for electron transfer over long distances (e.g., 100 Å and beyond). It is based on the excitation of generally supersonic solitons in a heated one-dimensional lattice with Morse interactions in a temperature range from low to physiological level. We study the influence of these supersonic excitations on electrons moving in the lattice. The lattice units (considered as "atoms") are treated by classical Langevin equations. The densities of the core electrons are in a first estimate represented by Gaussian densities, thus permitting to visualize lattice compressions as enhanced density regions. The evolution of excess, added free electrons is modeled in the tight-binding approximation using first Schrödinger equation and, subsequently, the assumption of local canonical equilibrium corresponding to an adiabatic approximation. The relaxation to thermal equilibrium is studied in a perturbative approach by means of the Pauli master equation. © 2009 Wiley Periodicals, Inc.