论文标题
传统超导体中均匀和静态外场的表面电阻和振幅模式
Surface resistance and amplitude mode under uniform and static external field in conventional superconductors
论文作者
论文摘要
我们根据准经典近似计算静态外部场下S波超导体的表面电阻。对于脏且相对干净的病例，进行了数值计算，研究了它们之间的吸收光谱的差异。以前在局部响应函数中已经研究的肮脏情况下的振幅模式也出现在非局部响应中。在干净的情况下，振幅模式的激发能量与间隙边缘的能量之间存在巨大的差异，而电子和外部场之间的耦合有效。因此，即使超导体相对干净，幅度模式也存在，但其对响应函数的贡献很小。这些行为在质上与实验结果一致，可以通过非扰动地考虑静态场来获得。
We calculate the surface resistance of s-wave superconductors under a static external field on the basis of the quasiclassical approximation. The numerical calculations are performed both for the dirty and relatively clean cases, and the difference in the absorption spectrum between them is investigated. The amplitude mode in the dirty case, which has been previously studied in the local response function, appears also in the nonlocal response. In the clean case, there is a large discrepancy between the excitation energy of the amplitude mode and the energy of the gap edge where the coupling between the electrons and the external field is effective. Therefore, the amplitude mode exists even when the superconductor is relatively clean, but its contribution to the response function is small. These behaviors, which are qualitatively consistent with the experimental results, are obtained by taking into account the static field nonperturbatively.
