arXiv:cond-mat/0401436 · Physical Review B
Pseudogap, competing order, and the coexistence of staggered flux and d -wave pairing in high-temperature superconductors
Sen Zhou, Ziqiang Wang
Abstract
We study the $t\text{\ensuremath{-}}J\text{\ensuremath{-}}V$ model of a doped Mott insulator in connection to high-${T}_{c}$ superconductors. The nearest neighbor Coulomb interaction $(V)$ is treated quantum mechanically on equal footing as the antiferromagnetic exchange interaction $(J)$. Motivated by the $SU(2)$ symmetry at half-filling, we construct a large-$N$ theory which allows a systematic study of the interplay between staggered flux order and superconductivity upon doping. We solve the model in the large-$N$ limit and obtain the ground state properties and the phase diagram as a function of doping. We discuss the competition and the coexistence of the staggered flux and the $d$-wave superconductivity in the underdoped regime and the disappearance of superconductivity in the overdoped regime.