J. Phys. IV France 114 (2004) 23
DOI: 10.1051/jp4:2004114004

Dimensional crossover and deconfinement in Bechgaard salts

T. Giamarchi¹, S. Biermann², A. Georges² and A. Lichtenstein<sup>3

1</sup>  University of Geneva, 24 Quai Ernest Ansermet, 1211 Geneva, Switzerland
    e-mail: thierry.giamarchi@physics.unige.ch
²  LPTENS-CNRS UMR 8549, 24 rue Lhomond, 75231 Paris Cedex 05, France
    e-mail: georges@lpt.ens.fr
³  University of Nijmegen, 6525 ED Nijmegen, The Netherlands
    e-mail: georges@lpt.ens.fr

Abstract
The Bechgaard salts are made of weakly coupled one dimensional chains. This particular structure gives the possibility to observe in these systems a dimensional crossover between a high temperature (or high energy) one dimensional phase and a two or three dimensional system. Since the filling of the chains is commensurate the system thus undergoes a deconfinement transition from a one dimensional Mott insulator to a two (or three) dimensional metal. Such a transition has of course a strong impact on the physical properties of these compounds, and is directly seen in transport measurements.

In order to describe such a transition a dynamical mean field method has been introduced (chain-DMFT). Using this method we investigate a system of coupled Hubbard chains and show that we can indeed reproduce the deconfinement transition. This allows to determine physical quantities such as the transport transverse to the chains and the shape of the Fermi surface and quasiparticle residues in the low temperature phase. Key words. Organic conductors - Luttinger liquid - Deconfinement

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