Europhys. Lett.
Volume 60, Number 2, October 2002
Page(s) 262 - 268
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 01 October 2002
DOI: 10.1209/epl/i2002-00345-2

Europhys. Lett., 60 (2) , pp. 262-268 (2002)

Temperature-driven crossover phenomena in the correlation lengths of the one-dimensional -J model

J. Sirker and A. Klümper

Theoretische Physik I, Universität Dortmund Otto-Hahn-Str. 4, D-44221 Dortmund, Germany

(Received 21 May 2002; accepted in final form 6 August 2002)

We describe a modified transfer matrix renormalization group (TMRG) algorithm and apply it to calculate thermodynamic properties of the one-dimensional $t\mbox{-}J$ model. At the supersymmetric point we compare with Bethe ansatz results and make direct connection to conformal field theory (CFT). In particular we study the crossover from the non-universal high- T lattice into the quantum critical regime by calculating various correlation lengths and static correlation functions. Finally, the existence of a spin-gap phase is confirmed.

71.10.Fd - Lattice fermion models (Hubbard model, etc.).
05.10.Cc - Renormalization group methods.
05.70.-a - Thermodynamics.

© EDP Sciences 2002