Hitchhiking transport in quasi-one-dimensional systems

TL;DR

This paper proposes a new model for charge transport in quasi-one-dimensional systems where mobile localized sites facilitate carrier movement, potentially explaining temperature-independent mobility and specific frequency responses.

Contribution

It introduces a hopping mechanism involving mobile localization sites in 1D chains, contrasting with traditional static-site models, and explores its implications for transport properties.

Findings

Mobility may become temperature independent due to mobile sites.

Transport exhibits frequency dependence similar to conventional hopping.

The model explains transport behavior in systems with significant atomic diffusion.

Abstract

In the conventional theory of hopping transport the positions of localized electronic states are assumed to be fixed, and thermal fluctuations of atoms enter the theory only through the notion of phonons. On the other hand, in 1D and 2D lattices, where fluctuations prevent formation of long-range order, the motion of atoms has the character of the large scale diffusion. In this case the picture of static localized sites may be inadequate. We argue that for a certain range of parameters, hopping of charge carriers among localization sites in a network of 1D chains is a much slower process than diffusion of the sites themselves. Then the carriers move through the network transported along the chains by mobile localization sites jumping occasionally between the chains. This mechanism may result in temperature independent mobility and frequency dependence similar to that for conventional hopping.