论文标题
在尖锐的结构壁壁上的超导体/铁磁性绝缘体结构中的状态和三重相关的准密度
Quasiparticle density of states and triplet correlations in superconductor/ferromagnetic-insulator structures across a sharp domain wall
论文作者
论文摘要
已知与超导体接触的铁磁绝缘子（FI）在FI/S界面处诱导态态密度的自旋分裂。这种自旋分裂导致库珀对减少其单线状态相关性并获得奇数频率的三胞胎相关性。我们考虑了FI中具有锋利的磁性域壁的扩散FI/S双层，并研究了状态的局部准粒子密度和三重态超导相关性。在域的共线对准的情况下，我们通过求解USADEL方程来获得分析结果。对于足够小的交换场或弱超导性，我们还找到了任意磁纹理的分析表达式，该表达式揭示了三重态分量矢量如何取决于FI的局部磁化。对于磁化和交换场的强度之间的任意角度，我们实际上解决了尖锐的域壁的问题。我们最终提出了基于FI/S/F堆栈的两个不同的设置，其中F是铁磁层，以滤除单线对并通过隧穿差分电导测量测量来检测三胞胎相关的存在。
A ferromagnetic insulator (FI) in contact with a superconductor (S) is known to induce a spin splitting of the BCS density of states at the FI/S interface. This spin splitting causes the Cooper pairs to reduce their singlet-state correlations and acquire odd-in-frequency triplet correlations. We consider a diffusive FI/S bilayer with a sharp magnetic domain wall in the FI and study the local quasiparticle density of states and triplet superconducting correlations. In the case of collinear alignment of the domains, we obtain analytical results by solving the Usadel equation. For a small enough exchange field or weak superconductivity, we also find an analytical expression for arbitrary magnetic textures, which reveals how the triplet component vector depends on the local magnetization of the FI. For an arbitrary angle between the magnetizations and the strength of the exchange field, we numerically solve the problem of a sharp domain wall. We finally propose two different setups based on FI/S/F stacks, where F is a ferromagnetic layer, to filter out singlet pairs and detect the presence of triplet correlations via tunneling differential conductance measurements.
