BAND MAPPING AND QUASI-PARTICLE SUPPRESSION IN THE ONE-DIMENSIONAL ORGANIC CONDUCTOR TTF-TCNQ

Dispersing 1D bands have been observed for the first time in an organi c conductor by high resolution photoemission experiments on TTF-TCNQ ( tetrathiafulvalene-tetracyanoquinodimethane). Their properties are ext remely unusual: the bandwidth is much larger than traditional estimate s, and the quasiparticle states are strongly renormalized, with no wei ght at the chemical potential. A deep pseudogap around the Fermi energ y persists, and even increases, up to room temperature. We also report a direct determination of k(F) in this material, and the observation of the opening of a Peierls gap in the low-temperature charge density wave phase.