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.

Electron Dynamics in Tight‐Binding Approximation ‐ the Influence of Thermal Anharmonic Lattice Excitations

“…On the other hand we have shown that the electron tunneling between energetic minima in the lattice is also influenced by solitons in the medium, however this is a more complex process. All the mentioned effects could help to understand the observed electron transfer (ET) over long distances with only small loss of energy [14][15][16][17][18].…”

“…Then solitons are excited due to the influence of the thermal embedding. However we do not have just one or two solitons, but many of them generated by the heat bath [17,18]. Indeed we see up to the range of physiological temperatures many relatively small solitons in the system which have a finite life-time up to a few picoseconds.…”

“…The details of the combination of tunneling and thermal activation are still to be explored, in particular the role of the thermal solitons. Anyhow we may already express the hope that this will contribute to the further exploration of the understanding of the observed electron transfer (ET) in biomolecules over long distances [14][15][16][17][18]. …”

Hopping Transport and Stochastic Dynamics of Electrons in Plasma Layers

“…This will be done in a subsequent work. In comparison to the adiabatic approach used in some previous works [9][10][11] for one and for two-dimensional systems, the great advantage is here that we describe directly fast kinetic processes in the layer and can estimated transport processes as demonstrated for the case of diffusion here. We assumed so far that the electron concentration is generated by doping and is rather low, the dynamics is mainly determined by the electron-atom and by the atom-interactions.…”

“…The supersonic soliton carrier proposed in Refs. [3][4][5][6][7][8][9][10] comes from anharmonicity in the lattice dynamics before the electron-lattice interaction is introduced. When the latter is added we can foresee a redefinition of the evolution with a new effective anharmonic Hamiltonian incorporating e,g.…”