arXiv:cond-mat/0303544 · Physical review. B, Condensed matter
Coexistence of dx2−y2 -wave superconductivity and antiferromagnetism induced by a staggered field
Yasuhiro Saiga, Masaki Oshikawa
Abstract
The two-dimensional $t\ensuremath{-}J$ model in a staggered field is studied by exact diagonalization of small clusters. For the low-hole-density region and a realistic value of $J/t,$ it is found that the presence of a staggered field strengthens the attraction between two holes. With increasing field, the ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$-wave superconducting correlations are enhanced while the extended-s-wave ones hardly change. This implies that coexistence of the ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$-wave superconducting order and the commensurate antiferromagnetic order occurs in a staggered field.