Optical experiments are reported for the metallic state of the linear chain compound (TMTSF)<Subscript>2</Subscript>ClO<Subscript>4</Subscript>. 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...</subscript></subscript>

We show that non-frustrated and frustrated ladders in a magnetic field can be systematically mapped onto an XXZ Heisenberg model in a longitudinal magnetic field in the limit where the rung coupling is the dominant one. This mapping is valid in the critical region where the magnetization goes...

We study the effect of spin-phonon coupling in small magnetic clusters, concentrating on a S=1/2 ring of 4 spins coupled antiferromagnetically. If the phonons are treated as classical variables, there is a critical value of the spin-phonon coupling above which a static distortion occurs. This is...

The chain-like ZrTe<Subscript>3</Subscript> compound undergoes a charge-density-wave (CDW) transition at T<Subscript>CDW</Subscript>=63 K, most strongly affecting the conductivity perpendicular to the chains. We measure the temperature (T) dependence of the optical reflectivity from the far infrared up to the ultraviolet with polarized...</subscript></subscript>

We present a comprehensive optical study of the narrow gap FeSb<Subscript>2</Subscript> semiconductor. From the optical reflectivity, measured from the far infrared up to the ultraviolet spectral range, we extract the complete absorption spectrum, represented by the real part σ<Subscript>1</Subscript>(ω) of the complex optical...</subscript></subscript>

We present the optical properties of Na<Subscript>0.7</Subscript>CoO<Subscript>2</Subscript> single crystals, measured over a broad spectral range as a function of temperature (T). The capability to cover the energy range from the far-infrared up to the ultraviolet allows us to perform reliable Kramers-Kronig transformation, in order to...</subscript></subscript>