We study the localization in the Hilbert space of a modified Tomonaga-Luttinger model. For the standard version of this model, the states are found to be extended in the basis of Slater determinants, representing the eigenstates of the noninteracting system. The linear dispersion which leads to the fact that these eigenstates are extended in the modified model is replaced by one with random level spacings modeling the complicated one-particle spectra of realistic models. The localization properties of the eigenstates are studied. The interactions are simplified and an effective one-dimensional Lloyd model is obtained. The effects of many-body energy correlations are studied numerically. The eigenstates of the system are found to be localized in Fock space for any strength of the interactions, but the localization is not exponential.

• Received 7 June 2000

DOI:https://doi.org/10.1103/PhysRevB.63.045106