Localization-delocalization transition has been examined for interacting one-dimensional fermion systems with the backward and the Umklapp scattering by use of the phase Hamiltonian. In this approach the localized state is represented as that where the phase variable of either charge or spin (or both of them) is pinned by impurities and then distorted spatially, i.e. glassy. The transition can be understood as the depinning process due to the quantum fluctuations and its boundary has been determined both from the localized region and from the delocalized region. The two different procedures are shown to yield same criterion for the transition.
Dans le cadre de la theorie du champ, on resout exactement le probleme aux valeurs propres dans un systeme de fermions a 1 dimension interagissant par un potentiel en fonction delta. Les etats propres de spin et d'energie sont representes sous une forme systematique et compacte. Les etats propres et les valeurs propres de l'energie sont specifies par deux ensembles de nombres quantiques, les moments de particule et les moments de spin, entre deux valeurs propres d'un moment angulaire de spin total et sa composante z
Electrons in one-dimensional disordered systems exhibit Anderson localization in the absence of mutual interactions. However the transition is possible between localized and delocalized state as the interaction is turned on. In this paper such interplay between Anderson localization and interactions has been examined for spin dependent Tomonaga model based on the phase Hamiltonian derived by the bosonization of the fermion field. The problem is the extention of the classical impurity pinning of the charge density wave to that of quantum systems with phase variables of not only charge but also spin. The critical value of the interaction constant has been derived by the use of selfconsistent-harmonic approximation to the nonlinearity.