论文标题
磁性绝缘子/超导体接口处的自旋电流注入
Spin current injection at magnetic insulator/superconductor interfaces
论文作者
论文摘要
与获得自旋电流传播的磁性顺序要求相反，没有磁性顺序的材料也被发现是有效的自旋导体。在这项工作中，我们研究了磁绝缘体和超导体之间界面处的自旋电流注入。我们主要对顺磁绝缘子/超导体界面感兴趣，但是，我们的模型还描述了铁磁相。我们使用Schwinger玻感形式主义来描述磁性绝缘体，并应用了标准BCS理论来处理超导体层。在正常的金属限制下，我们的结果与预期的结果一致。例如，我们在低温下发现了正确的旋转电流行为$ i \大约t^{3/2} $。此外，我们的模型显示在靠近超导型准粒子相干性的高导体过渡温度的温度下，自旋电流注入的峰值明显。还研究了磁场在自旋电流注入中的作用。
Opposite to the common idea of a magnetic order requirement to obtain spin current propagation, materials with no magnetic ordering have also been revealed to be efficient spin conductors. In this work, we investigate the spin current injection at the interface between a magnetic insulator and a superconductor. We are mainly interested in the paramagnetic insulator/superconductor interface however, our model also describes the ferromagnetic phase. We used the Schwinger bosonic formalism to describe the magnetic insulator and standard BCS theory was applied to treat the superconductor layer. In the normal-metal limit, our results are in agreement with the expected ones. For example, we found the correct spin current behavior $I\approx T^{3/2}$ at low temperature. In addition, our model shows a pronounced peak in the spin current injection at temperatures close to the superconductor transition temperature due to the superconducting quasiparticle coherence. The role of magnetic fields in the spin current injection is also investigated.
