Comment on fluctuation paraconductivity in quasi-one-dimensional systems

Abstract

The results of Allender, Bray, and Bardeen for the paraconductivity above the Peierls transition in a one-dimensional system are modified to include the effects of high-frequency (optical) phonons and interchain coupling. A very good agreement with experiment on tetrathiofulvalene-tetracyanoquinodimethane (TTF-TCNQ) is thus obtained. In particular, it is shown that a mean-field theory based on low-frequency (acoustic) phonons is not consistent with the observed increase and temperature behavior of the conductivity above $T_p$, while high-frequency phonons (${\omega }_{{2p}_F}\gg T$) fully account for the observed conductivity in the range $T_p\lesssim T\lesssim 2T_p$.