arXiv:cond-mat/0401307 · Physical Review Letters
Enhancement of Pairing Correlation by t′ in the Two-Dimensional Extended t−J Model
C. T. Shih, Ting-Kuo Lee, R. Eder, Chung‐Yu Mou, Y. C. Chen
Abstract
We investigate the effects of the next-nearest-neighbor (${t}^{\ensuremath{'}}$) and the third-nearest-neighbor (${t}^{\ensuremath{'}\ensuremath{'}}$) hopping terms on superconductivity correlation in the 2D hole-doped extended $t\ensuremath{-}J$ model based on the variational Monte Carlo, mean-field calculation and exact diagonalization method. Despite the diversity of the methods employed, the results all point to a consistent conclusion: While the $d$-wave superconductivity correlation is slightly suppressed by ${t}^{\ensuremath{'}}$ and ${t}^{\ensuremath{'}\ensuremath{'}}$ in underdoped regions, it is greatly enhanced in the optimal and overdoped regions. The optimal ${T}_{c}$ is a result of the balance of these two opposite trends.