SUPPRESSION OF LOCALIZATION IN QUASI-1D SYSTEMS BY ELECTROMAGNETIC FLUCTUATIONS

Localization effects in quasi-ID compounds are suppressed by thermal electromagnetic fluctuations at temperatures T much greater than hBAR/[tau.(hV(F)epsilon(perpendicular-to)BAR/e2)1/3], where tau is the mean free time of an electron with respect to backscattering, epsilon(perpendicular-to) is the dielectric constant of the lattice in the direction transverse with respect to the conducting chains, and V(F) is the Fermi velocity. The conductivity can therefore be described by the Drude formula in this case. It is assumed that the condition e2/(epsilon(perpendicular-to) V(F)hBAR) much less than 1 holds, i.e., that the electron-electron interaction is weak. A situation approaching a quasi- 1D situation arises in 3D semiconductors and semimetals in high magnetic fields. In this case localization effects are suppressed by thermal fluctuations under the same conditions as in quasi-1D conductors.