Controlling spin pumping into superconducting Nb by proximity-induced spin-triplet Cooper pairs
Controlling spin pumping into superconducting Nb by proximity-induced spin-triplet Cooper pairs
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DOI：
10.1038/s42005-023-01384-w
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发表时间：
2023-10-11
影响因子：
5.5
通讯作者：
Cohen，L. F.
中科院分区：
文献类型：
--
作者：
Chan，A. K.;Cubukcu，M.;Cohen，L. F.
邻近诱导的长程自旋三重态超电流是在超导/铁磁异质结构中产生的，这对超导自旋电子学领域很重要。多层堆叠Nb/Cr/Fe/Cr/Nb已经被示出在制造成约瑟夫森结器件时支持这样的电流。然而，在约瑟夫森结结构之外的超导体中可控地产生纯自旋电流是进展的瓶颈。最近，铁磁共振被提出作为一个可能的方向，签名的纯超导电流的创建是一个增强的吉尔伯特阻尼超导临界温度以下，但必要的条件仍然很差。在这里，我们证明，泵纯自旋电流到超导体中存在的外部磁场是唯一可能的，当支持邻近诱导的自旋三重态效应的条件得到满足。我们的研究是纯自旋超电流产生的重要一步，大大推进了超导自旋电子学领域。
Proximity-induced long-range spin-triplet supercurrents, important for the field of superconducting spintronics, are generated in superconducting/ferromagnetic heterostructures when interfacial magnetic inhomogeneities responsible for spin mixing and spin flip scattering are present. The multilayer stack Nb/Cr/Fe/Cr/Nb has been shown to support such currents when fabricated into Josephson junction devices. However, creating pure spin currents controllably in superconductors outside of the Josephson junction architecture is a bottleneck to progress. Recently, ferromagnetic resonance was proposed as a possible direction, the signature of pure supercurrent creation being an enhancement of the Gilbert damping below the superconducting critical temperature, but the necessary conditions are still poorly established. Here, we demonstrate that pumping pure spin currents into a superconductor in the presence of an external magnetic field is only possible when conditions supporting proximity-induced spin-triplet effects are satisfied. Our study is an important step forward for pure spin supercurrent creation, considerably advancing the field of superconducting spintronics.