Superconductivity Driven by the Interband Coulomb Interaction and Implications for the Superconducting Mechanism of MgB2
Superconductivity Driven by the Interband Coulomb Interaction and Implications for the Superconducting Mechanism of MgB2
复制标题
带间库仑相互作用驱动的超导性及其对 MgB2 超导机制的启示
DOI：
10.1143/jpsj.70.1218
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发表时间：
2001
影响因子：
1.7
通讯作者：
M. Imada
中科院分区：
文献类型：
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作者：
M. Imada
在扩展的双带Hubbard模型中研究了带间交换库仑排斥的超导机制，该模型中一个宽带穿过费米能级，并与一个位于较低能量的窄带共存.我们应用新发展的路径积分重整化群方法可靠地计算配对关联。的相关性显示出显着的增强，在中等幅度的交换库仑排斥采取小于现场排斥较窄的频带。配对对称性是s波，而它有非常规的相位与相反的符号之间的两个频带上的序参数，在协议的平均场预测。由于最近发现的超导体MgB2的能带结构与我们的模型基本相似，我们认为，目前的结果为理解MgB2以及这类具有良好金属导电性的多带材料的超导机制提供了相关的线索。
Superconducting mechanism mediated by interband exchange Coulomb repulsion is examined in an extended two-band Hubbard models with a wide band crossing the Fermi level and coexisting with a narrower band located at moderately lower energy. We apply newly developed path-integral renormalization group method to reliably calculate pairing correlations. The correlation shows marked enhancement at moderate amplitudes of the exchange Coulomb repulsion taken smaller than the on-site repulsion for the narrower band. The pairing symmetry is s-wave while it has unconventional phases with the opposite sign between the order parameters on the two bands, in agreement with the mean-field prediction. Since the band structure of recently discovered superconductor MgB 2 shares basic similarities with our model, we propose that the present results provide a relevant clue for the understanding of the superconducting mechanism in MgB 2 as well as in this class of multi-band materials with good metallic conduction in the norm...
DOI：
10.1007/bf01303701
发表时间：
1986-01-01
期刊：
ZEITSCHRIFT FUR PHYSIK B-CONDENSED MATTER
影响因子：
--
作者：
BEDNORZ, JG;MULLER, KA
通讯作者：
MULLER, KA