Evidence for collective linear conduction in the Peierls conductor o-TaS_3

Abstract

Using photoconduction study we demonstrate that the low-temperature Ohmic conduction of TaS${}_3$ is not provided by single-particle excitations -- electrons and holes excited over the Peierls gap. Instead, the low-temperature Ohmic conduction is mostly provided by collective excitations having the activation energy about half of the Peierls gap value and shunting the contribution of electrons and holes.

RevTeX4, 4 pages, 4 figures. Revised version with more detailed discussion. To be published in Physical Review Letters