Physical review. B, Solid state
Localization versus delocalization in the one-dimensional Tomonaga model with impurities
S. T. Chui, J. W. Bray
Abstract
We examine localization and delocalization in the one-dimensional Tomonaga model with impurities. We expand the density autocorrelation function in a perturbation series in the impurity coupling ${U}_{\ensuremath{\perp}}$. We then relate the terms in this series to the partition functions ${Q}_{N}$ for an $N$-particle two-dimensional Coulomb gas. After obtaining new stringent bounds on ${Q}_{N}$, we use these bounds and the analytic properties of the perturbation series to predict localization. In contradiction of earlier results, we find that the electrons are localized (delocalized) for electron-electron interactions $\frac{{U}_{\ensuremath{\parallel}}}{2\ensuremath{\pi}{v}_{F}}$ greater than (less than) -5/13, independent of ${U}_{\ensuremath{\perp}}$ ${v}_{F}$ is the Fermi velocity). This is the first time to our knowledge that a localization transition has been studied by such a bounded-series technique.