Competition between stripes and pairing in at−t′−Jmodel

Abstract

As the number of legs $n$ of an $n$-leg, $t\ensuremath{-}J$ ladder increases, density-matrix renormalization group calculations have shown that the doped state tends to be characterized by a static array of domain walls and that pairing correlations are suppressed. Here we present results for a ${t\ensuremath{-}t}^{\ensuremath{'}}\ensuremath{-}J$ model in which a diagonal, single-particle, next-nearest-neighbor hopping ${t}^{\ensuremath{'}}$ is introduced. We find that this can suppress the formation of stripes and, for ${t}^{\ensuremath{'}}$ positive, enhance the ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$-like pairing correlations. The effect of ${t}^{\ensuremath{'}}>0$ is to cause the stripes to evaporate into pairs and for ${t}^{\ensuremath{'}}<0$ to evaporate into quasiparticles. Results for $n=4$ and 6 $n$-leg ladders are discussed.