Hopping Conductivity in "One-Dimensional" Disordered Compounds

Careful consideration of the hopping conductivity in "one-dimensional" disordered compounds revels that there is a low-temperature region in which the conductivity is given by $\ln \sigma \sim -{\left(\frac{T_0}{T}\right)}^{\frac{1}{2}}$. Further empirical evidence is presented which supports this conclusion. The upper bound on the conductivity obtained by Kurkijarvi is seen not to be relevant for actual materials under consideration.