Anisotropic electrodynamics of low dimensional metals: Optical studies of (TMTSF)2ClO4
Department of Physics, University of California, Los Angeles, CA 90095-1547, USA
2 Laboratorium fr Festkrperphysik, Eidgenssische Technische Hochschule, 8093 Zrich, Switzerland
Published online: 15 October 1999
Optical experiments are reported for the metallic state of the linear chain compound (TMTSF)2ClO4. For the electric field polarized both along the highly (a) and intermediately (b ) conducting directions, a zero energy (ZE) mode and a finite energy mode (FE) are observed. The large anisotropy in the spectral weight of the FE mode is consistent with the band structure, however the spectral weight of the ZE mode is surprisingly isotropic. In the least conducting (c *) direction, the low frequency optical conductivity along with the dc conductivity indicate the presence of a (small) Drude component only at temperatures below 10 K. These observations provide evidence for a correlation induced semimetallic state, with a 3D to 2D crossover with increasing temperature.
PACS: 78.20.-e – Optical properties of bulk materials and thin films / 71.10.Pm – Fermions in reduced dimensions (anyons, composite fermions, Luttinger liquid, etc.)
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1999