Europhys. Lett., 60 (2) , pp. 262-268 (2002)
Temperature-driven crossover phenomena in the correlation lengths of the one-dimensional -J modelJ. 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 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.
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