gossamer超导体基态相图的研究

Phase Diagram of Gossamer Superconductors in t t-t′-J-U Model

在t-t-′J-U模型下,应用Gutzwiller平均场近似的方法,研究了gossamer超导体基态情况下的相图。结果表明,大U极限下,在欠掺杂区域,反铁磁序和d波超导序在很大的掺杂浓度范围内都共存。随着次近邻跃迁的增大,超导序参数在欠掺杂区域受到抑制,在最佳掺杂和过掺杂区域得到加强,从而导致反铁磁序和d波超导序共存区域变大,d波超导序在较大的掺杂浓度范围内一直存在。这些都与数值计算结果的趋势一致。

The phase diagrams of gossamer superconductors are studied in a renormalized mean-field theory based on the Gutzwiller approximation within the t-t＇-J-U model. In the large-U limit, The results show that the antiferromagnetic （AF） order coexists with the d-wave superconductivity （dSC） in the underdoped region around the doping δ≈0. 1. The dSC order parameter is slightly suppressed in the underdoped regions, and greatly enhanced in the optimal and overdoped regions with the increasing of the t＇. As a result, the coexistence region of the AF and dSC is extended to higher doping and the dSC order persists for a larger doping.