论文标题
半无限超导体和分层超导体的过热领域在扩散极限：基于显微镜理论的结构优化
Superheating fields of semi-infinite superconductors and layered superconductors in the diffusive limit: structural optimization based on the microscopic theory
论文作者
论文摘要
我们通过使用良好的bcs理论中的准绝妙绿色功能形式主义，研究了在扩散极限中的半无限超导体和分层超导体的过热领域。耦合的Maxwell-Usadel方程是自一求解的，以获得磁场的空间分布，筛选电流密度，穿透深度和配对电位。我们发现在扩散限制中，半无限超导体的过热字段由$ h_ {sh} = 0.795 h_ {c0} $在温度$ t \至0 $下给出。这里$ h_ {c0} $是零温度下的热力学关键场。另外，我们评估了分层超导体的$ h_ {sh} $作为层厚度的功能（$ d $）的功能，并确定最大的厚度，以最大程度地提高$ h_ {sh} $的各种材料组合。还讨论了基于伦敦近似的$ h_ {sh}（d）$的定性解释。这项工作的结果可用于提高颗粒加速器的超导RF谐振腔的性能。
We investigate the superheating fields $H_{sh}$ of semi-infinite superconductors and layered superconductors in the diffusive limit by using the well-established quasiclassical Green's function formalism of the BCS theory. The coupled Maxwell-Usadel equations are self-consistently solved to obtain the spatial distributions of the magnetic field, screening current density, penetration depth, and pair potential. We find the superheating field of a semi-infinite superconductor in the diffusive limit is given by $H_{sh} = 0.795 H_{c0}$ at the temperature $T \to 0$. Here $H_{c0}$ is the thermodynamic critical-field at the zero temperature. Also, we evaluate $H_{sh}$ of layered superconductors in the diffusive limit as functions of the layer thicknesses ($d$) and identify the optimum thickness that maximizes $H_{sh}$ for various materials combinations. Qualitative interpretation of $H_{sh}(d)$ based on the London approximation is also discussed. The results of this work can be used to improve the performance of superconducting rf resonant cavities for particle accelerators.
