非磁杂质对高Tc超导电性的影响

本文证明了在氧化物高T_c超导体的Anderson晶格模型中,由于序参量是能量的函数,非磁掺杂也具有拆对效应,在稀掺杂情况下,求出了T_c随杂质浓度增加而线性下降的规律,与实验结果相符,文中还计算了掺杂对超导态密度中能隙的影响,结果表明,当非磁掺杂浓度增加时,零温能隙的减小比T_c的下降慢得多,从而在转变为正常态之前可能不出现类似通常BCS超导体磁性掺杂的无能隙区。 关键词：

INFLUENCE OF NON-MAGNETIC IMPURITIES ON THE HIGH-Tc SUPERCONDUCTIVITY

In this paper, we have proved that the non -magnetic doping can also produce pair-breaking effect in the Anderson lattice model of the high-T_c cuprate superconductorts due the energy dependence of the order parameter. In the case of dilute doping, we have obtained a linear decreasing behavior of T_c with the increasing of non-magnetic impurity concentration in agreement with experimental results. Furthermore, we have also calculated the influence of doping on the superconducting energy gap in the density of states. The results indicate that the decreasing of the gap at T = 0 is much slower than the dropping of T_c with the increasing of non-magnetic impurities. Therefore, the gapless region may not appear before the system transforms into the normal state in different from the conventional BCS superconductors with magnetic impurities.