J. Phys. I France
Volume 6, Numéro 12, December 1996
Page(s) 1719 - 1726
DOI: 10.1051/jp1:1996184
J. Phys. I France 6 (1996) 1719-1726

Unconventional Electrodynamic Response of the Quasi-One-Dimensional Organic Conductor (TMTSF) $\mathsf{_2}$ClO $\mathsf{_4}$

N. Cao1, T. Timusk1 and K. Bechgaard2

1  Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada L8S 4M1
2  Department of Solid State Physics, Risø National Laboratory, 4000 Roskilde, Denmark

(Received 18 June 1996, revised 1 August 1996, accepted 18 August 1996)

The polarized optical reflectance of the quasi-one-dimensional organic conductor (TMTSF) 2ClO 4 has been measured along the chain axis from the far-infrared (~8 meV) to the visible (~1 eV) at temperatures between 10 and 300 K. A self-consistent description of the far infrared reflectance and the high metallic conductivity of (TMTSF) 2ClO 4 implies that a narrow mode at zero frequency carries the transport current, and there is no Drude peak corresponding to single particle motion. As the temperature is lowered below 100 K, the spectral weight of the narrow mode grows in parallel with several bands in the far infrared: a broad band with a gap-like onset at (2 $\Delta\simeq 170~{\rm cm}^{-1}$) and several low lying phonons. These observations are consistent with a process of collective charge transport by sliding charge density wave.

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