Interacting electrons in 1D: Applicability of Hubbard models

Stefan Soeffing, Sebastian Eggert

Q. P. Li, X. C. Xie

We study the transport properties of one-dimensional (1D) interacting fermions through a barrier by numerically calculating the Kohn charge stiffness constant and the relative Drude weight. We find that the transport properties of the 1D Hubbard model are quite different from those of the 1D spinless fermion model. For example, the presence of the attractive interaction between electrons in the 1D Hubbard model actually suppresses the dc conductance, while a small repulsive interaction enhances the dc conductance. These results show that the spin degree of freedom plays an important role in the transport properties of the 1D interacting fermion systems.

Niyazi Bulut, Douglas J. Scalapino

J. M. P. Carmelo, Tilen Čadež

The momentum, electronic density, spin density, and interaction dependences of the exponents that control the ( k , ω ) -plane singular features of the σ = ↑ , ↓ one-electron spectral functions of the 1D Hubbard model at finite magnetic field are studied. The usual half-filling concepts of one-electron lower Hubbard band and upper Hubbard band are defined in terms of the rotated electrons associated with the model Bethe-ansatz solution for all electronic density and spin density values and the whole finite repulsion range. Such rotated electrons are the link of the non-perturbative relation between the electrons and the pseudofermions. Our results further clarify the microscopic processes through which the pseudofermion dynamical theory accounts for the one-electron matrix elements between the ground state and excited energy eigenstates.

D.K. Ghosh

ARMEN N. KOCHARIAN, P. S. Ovnanyan