Eur. Phys. J. B 5, 395-402 (1998)
https://doi.org/10.1007/s100510050459

Interaction versus dimerization in one-dimensional Fermi systems^*

Institut für Physik, Universität Augsburg, 86135 Augsburg, Germany

Corresponding author: ^a This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 11 February 1998
Revised: 1 April 1998
Accepted: 30 April 1998
Published online: 15 October 1998

Abstract

In order to study the effect of interaction and lattice distortion on quantum coherence in one-dimensional Fermi systems, we calculate the ground state energy and the phase sensitivity of a ring of interacting spinless fermions on a dimerized lattice. Our numerical DMRG studies, in which we keep up to 1000 states for systems of about 100 sites, are supplemented by analytical considerations using bosonization techniques. We find a delocalized phase for an attractive interaction, which differs from that obtained for random lattice distortions. The extension of this delocalized phase depends strongly on the dimerization induced modification of the interaction. Taking into account the harmonic lattice energy, we find a dimerized ground state for a repulsive interaction only. The dimerization is suppressed at half filling, when the correlation gap becomes large.