51 research outputs found
Electronic structure of the quasi-one-dimensional organic conductor TTF-TCNQ
We study the electronic structure of the quasi-one-dimensional organic
conductor TTF-TCNQ by means of density-functional band theory, Hubbard model
calculations, and angle-resolved photoelectron spectroscopy (ARPES). The
experimental spectra reveal significant quantitative and qualitative
discrepancies to band theory. We demonstrate that the dispersive behavior as
well as the temperature-dependence of the spectra can be consistently explained
by the finite-energy physics of the one-dimensional Hubbard model at metallic
doping. The model description can even be made quantitative, if one accounts
for an enhanced hopping integral at the surface, most likely caused by a
relaxation of the topmost molecular layer. Within this interpretation the ARPES
data provide spectroscopic evidence for the existence of spin-charge separation
on an energy scale of the conduction band width. The failure of the
one-dimensional Hubbard model for the {\it low-energy} spectral behavior is
attributed to interchain coupling and the additional effect of electron-phonon
interaction.Comment: 18 pages, 9 figure
Resistência de clones e híbridos de porta-enxertos de citros à gomose de tronco causada por Phytophthora parasitica
Diversity of metaxylem vessel elements in three Syagrus palms (Arecaceae) of different habits
Bedload transport monitoring in a small upland catchment
International audienceCommunication orale faite lors du 8th IAG International Conference on Geomorphology, Paris, 27-31 August 2013
Bedload transport monitoring at Draix
International audienceConférence invitée lors du International Workshop on Monitoring Bedload and Debris-Flows in Mountain Basins, Free University of Bolzano, Italy, 10-12 October 2012
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