title: Re-integerization of fractional charges in the correlated quarter-filled band.
abstract: Previous work has demonstrated the existence of soliton defect states with charges +/-e/2 in the limits of zero and infinite on-site Coulomb interactions in the one-dimensional (1D) quarter-filled band. For large but finite on-site Coulomb interaction, the low temperature 2kF bond distortion that occurs within the 4kF bond-distorted phase is accompanied by charge ordering on the sites. We show that a "re-integerization" of the defect charge occurs in this bond-charge-density-wave state due to a "binding" of the fractional charges. We indicate briefly possible implications of this result for mechanisms of organic superconductivity.
authors.affiliation: Department of Physics, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: R T
authors.initials: RT
authors.lastname: Clay
authors.forename: S
authors.initials: S
authors.lastname: Mazumdar
authors.forename: D K
authors.initials: DK
authors.lastname: Campbell