Spectroscopic signatures of spin-charge separation in the   quasi-one-dimensional organic conductor TTF-TCNQ
  The electronic structure of the quasi-one-dimensional organic conductor TTF-TCNQ is studied by angle-resolved photoelectron spectroscopy (ARPES). The experimental spectra reveal significant discrepancies to band theory. We demonstrate that the measured dispersions can be consistently mapped onto the one-dimensional Hubbard model at finite doping. This interpretation is further supported by a remarkable transfer of spectral weight as function of temperature. The ARPES data thus show spectroscopic signatures of spin-charge separation on an energy scale of the conduction band width. 
R. Claessen, M. Sing, U. Schwingenschloegl, P. Blaha, M. Dressel, and   C.S. Jacobsen