We describe a modified transfer matrix renormalization group (TMRG) algorithm and apply it to calculate thermodynamic properties of the one-dimensional t-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.
@article{arxiv.cond-mat/0212369,
title = {Temperature driven crossover phenomena in the correlation lengths of the one-dimensional t-J model},
author = {J. Sirker and A. Klümper},
journal= {arXiv preprint arXiv:cond-mat/0212369},
year = {2007}
}