Hitchhiking transport in quasi–one-dimensional systems

Department of Physics and Engineering Physics, University of Saskatchewan Saskatoon, SK S7N 5E2, Canada

Received: 15 March 2005
Accepted: 6 July 2005

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.