论文标题
具有杂质超导体的真实空间多散射理论
Real-space multiple scattering theory for superconductors with impurities
论文作者
论文摘要
我们使用筛选的korringa-kohn-rostoker（KKR）方法在实空间中实现Bogoliubov-De Gennes（BDG）方程。这使我们能够自以为是的3D晶体的超导状态，包括具有完整的正常状态DFT带结构的替代杂质。我们将理论框架应用于具有杂质的批量NB。没有杂质，NB具有各向异性间隙结构，在费米水平周围具有两个不同的峰。在存在非磁性杂质的情况下，由于两个散装超导间隙之间的散射，这些峰被扩大，但是峰保持分离。作为BDG方程的自洽实际空间解决方案的第二个示例，我们检查了嵌入非驱动的大量金属宿主中的超导群集。这使我们能够估计超导体的相干长度，并且我们表明，在我们的框架内，超导体的连贯长度与间隙大小的倒数有关，就像在批量BCS理论中一样。
We implement the Bogoliubov-de Gennes (BdG) equation in real-space using the screened Korringa-Kohn-Rostoker (KKR) method. This allows us to solve, self-consistently, the superconducting state for 3d crystals including substitutional impurities with a full normal-state DFT band structure. We apply the theoretical framework to bulk Nb with impurities. Without impurities, Nb has an anisotropic gap structure with two distinct peaks around the Fermi level. In the presence of non-magnetic impurities those peaks are broadened due to the scattering between the two bulk superconducting gaps, however the peaks remain separated. As a second example of self-consistent real-space solutions of the BdG equations we examine superconducting clusters embedded within a non-superconducting bulk metallic host. This allows us to estimate the coherence length of the superconductor and we show that, within our framework, the coherence length of the superconductor is related to the inverse of the gap size, just as in bulk BCS theory.
