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The European Physical Journal B
ISSN: 1434-6028 (printed version)
ISSN: 1434-6036 (electronic version)
Abstract Volume 5 Issue 3 (1998) pp 395-402
Interaction versus dimerization in one-dimensional Fermi systems
C. Schuster (b), U. Eckern
Institut für Physik, Universität Augsburg, 86135 Augsburg, Germany
Received: 11 February 1998 / Revised: 1st April 1998 / Accepted: 30 April 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.
PACS. 71.10.-w Theories and models of many electron systems - 75.10.Jm Quantized spin models
(b) email: cosima.schuster@physik.Uni-Augsburg.DE
Article in PDF format (362 KB)
Online publication: October 26, 1998
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