Vibron transport in macromolecular chains

TL;DR

This paper investigates vibron transport mechanisms in biological macromolecular chains using a modified Holstein polaron model, revealing how diffusivity varies with coupling strength and temperature, with implications for nanostructures.

Contribution

It introduces a detailed analysis of vibron self-trapping and diffusivity in macromolecular chains considering temperature effects and adiabaticity, extending understanding of vibron transport in biological and nanostructured materials.

Findings

Vibron diffusivity decreases smoothly with increased vibron-phonon coupling in non-adiabatic regimes.

In adiabatic regimes, the diffusivity dependence becomes discontinuous at a critical point.

Critical coupling depends on temperature, relevant at room temperature for biological systems.

Abstract

We study the hopping mechanism of the vibron excitation transport in the simple 1D model of biological macromolecular chains. We supposed that the vibron interaction with thermal oscillations of the macromolecular structural elements will result in vibron self -trapping, and the formation of the partial dressed vibron state. With use of the modified Holstein polaron model, we calculate vibron diffusivity in dependence of the basic system parameters and temperature. We obtain that the vibron diffusivity smoothly decreases in non adiabatic limit when the strength of the vibron-phonon coupling grows. However this dependence becomes by discontinuous one in case of growth of the adiabaticity of the system. The value of the critical point depends of the system temperature, and at room temperatures it belongs to the low or intermediate coupling regime. We discuss an application of these results to study of vibron transport to 3D bundles of such macromolecules chains considering it as polymer nanorods and to 2D polymer films organized from such macromolecules.