Thermodynamics of a superconductor with strongly bound Cooper pairs
Thermodynamics of a superconductor with strongly bound Cooper pairs
复制标题
具有强束缚库珀对的超导体的热力学
DOI：
10.1103/physrevb.60.3499
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发表时间：
1999
影响因子：
3.7
通讯作者：
U. Schollwöck
中科院分区：
文献类型：
--
作者：
M. Keller;W. Metzner;U. Schollwöck
本文通过在局域近似下求解吸引Hubbard模型的自洽T矩阵方程，研究了强束缚库珀对超导体的热力学性质。我们确定的转变温度作为在四分之一填充的相互作用强度的函数，并计算超导序参量的温度依赖性，比热，自旋磁化率，和在正常和超导相的本地对的密度。明显偏离BCS行为已经被发现为中等的相互作用，超导设置在一个临界温度以上的费米液体行为的相干温度。
We study the thermodynamics of a superconductor with strongly bound Cooper pairs by solving the self-consistent T-matrix equations for the attractive Hubbard model within a local approximation. We determine the transition temperature as a function of the interaction strength at quarter filling, and compute the temperature dependence of the superconducting order parameter, the specific heat, the spin susceptibility, and the density of local pairs in the normal and superconducting phase. Pronounced deviations from BCS behavior are found already for moderate interactions, where superconductivity sets in at a critical temperature above the coherence temperature for Fermi liquid behavior.