Numerical Study of the Pairing Correlation of the t-J Type Models

We reported that the pair-pair correlation function of the two-dimensional t-J model does not have long-range d-wave superconducting correlations in the interesting parameter range of $J/t \leq 0.5$. The power-Lanczos method is used under the assumption of monotonic behavior. This assumption has been well checked in the two-dimensional t-J and attractive Hubbard model. Here we re-examine this criterion of monotonic behavior of the pairing correlation function for the one-dimensional and two-leg t-J ladder where other accurate numerical results are available. The method seems to be working well.