自旋三重态库珀对的界面工程用于自旋阀实现
Interface engineering of spin triplet Cooper pairs for spin-valve implementation
- School of Physical Sciences, National Institute of Science Education and Research (NISER)（国家科学教育与研究学院物理科学学院）
- Homi Bhabha National Institute（霍米·巴巴国立研究所）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究通过界面工程在Nb/Pt界面引入粗糙度以增强自旋三重态库珀对转换，实现Nb/Pt/Ni/Pt/Nb器件中的自旋阀响应，为超导自旋电子学提供新途径。
AI中文摘要：
在适当条件下，自旋单重态库珀对可以在超导体/重金属界面转换为等自旋三重态对。在载流条件下，这些三重态关联可通过预测的超电流自旋霍尔效应在重金属中产生非平衡自旋矩。在此，我们证明这种电流诱导的三重态自旋矩与铁磁层的磁矩相结合，能够在Nb/Pt/Ni/Pt/Nb垂直纳米器件中实现磁性自旋阀响应。该自旋阀效应的幅度取决于Nb/Pt界面处单重态-三重态库珀对转换的效率。为了促进有效的三重态生成，我们特意引入界面粗糙度，以在Nb/Pt界面产生有限的Rashba自旋轨道耦合，并在Ni界面引入磁矩的面外分量。相反，在测量分辨率内，具有光滑界面的器件未观察到明显的自旋阀响应。由于Ni层的磁矩和Pt层中电流诱导的三重态自旋矩可分别通过磁场和偏置电流独立切换，因此自旋阀可通过任一参数进行控制。这些结果展示了一种在超导自旋电子学应用中直接利用自旋极化三重态库珀对的新方法。
英文摘要：
Spin singlet Cooper pairs can be converted into equal-spin triplet pairs at a superconductor/heavy-metal interface under suitable conditions. Under current carrying conditions, these triplet correlations can give rise to a non equilibrium spin moment in the heavy metal through the predicted supercurrent spin-Hall effect. Here we demonstrate that this current induced triplet spin moment, in conjunction with the magnetic moment of a ferromagnetic layer, can enable a magnetic spin-valve response in Nb/Pt/Ni/Pt/Nb vertical nano-devices. The magnitude of this spin-valve effect depends on the efficiency of singlet-triplet Cooper pair conversion at the Nb/Pt interface. In order to facilitate efficient triplet generation, we deliberately introduced interfacial roughness to introduce finite Rashba spin-orbit coupling at the Nb/Pt interface and an out-of-plane component of magnetic moment at the Ni interface. In contrast, no discernible spin-valve response was observed in devices with smooth interfaces within measurement resolutions. Since the magnetic moment of the Ni layer and the current-induced triplet spin moment in the Pt layer are independently switchable using a magnetic field and bias current, respectively, the spin valve can be controlled via either parameters. These results demonstrates a novel approach to directly utilizing the spin polarized triplet Copper pairs in superconducting spintronic applications.
