Confinement by charge gap in organic conductor Bechgaard salts

Abstract

In Bechgaard salts, which are effectively half-filling due to dimerization, a confinement has been found for the large charge gap in the optical experiments. In order to understand the crucial role of the charge gap, the irrelevance of interchain hopping corresponding to the confinement is calculated for two-coupled chains of quarter-filled Hubbard model with dimerization. It is demonstrated that a transition from deconfinement to confinement occurs when the charge gap induced by the dimerization becomes larger than the interchain hopping.