Giant spin polarization and a pair of antiparallel spins in a chiral superconductor
Giant spin polarization and a pair of antiparallel spins in a chiral superconductor
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DOI：
10.1038/s41586-022-05589-x
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发表时间：
2023-01-19
期刊：
影响因子：
64.8
通讯作者：
Yamamoto, H. M.
中科院分区：
文献类型：
--
作者：
Nakajima, R.;Hirobe, D.;Yamamoto, H. M.
手性分子可以表现出自旋选择性电荷发射，即手性诱导的自旋选择性(1，2)。尽管分子的组成元素是轻元素，但它们的自旋极化可以接近甚至超过典型的铁磁体。这种强大的能力可能导致在手性自旋电子学(2)领域的应用。尽管自旋选择性的来源尚不清楚，但基于实验结果，已经提出了两种微观现象：有效地增强了自旋-轨道相互作用(3)和由一对相反的极化自旋表示的手性(4，5)。然而，这些假说仍有待验证。本文报道了在超导转变温度附近用磁阻测量同时观测到有机手性超导体中的这两种现象。通过空间映射交流电激励中的自旋极性，证明了一对相反极化的自旋。得到的自旋极化比Edelstein效应(6-10)高出几个数量级，这表明自旋-轨道相互作用得到了有效的增强。我们的结果证明了手性分子自旋积累的固态模拟，并可能为它们的分子对应的起源提供线索。此外，自旋电流来源的创新能力将为超导自旋电子学研究注入活力(11)。
Chiral molecules can exhibit spin-selective charge emission, which is known as chirality-induced spin selectivity(1,2). Despite the constituent light elements of the molecules, their spin polarization can approach or even exceed that of typical ferromagnets. This powerful capability may lead to applications in the chiral spintronics(2) field. Although the origin of spin selectivity is elusive, two microscopic phenomena have been suggested based on experimental results: effective enhancement of spin-orbit interactions(3) and chirality represented by a pair of oppositely polarized spins(4,5). However, the hypotheses remain to be verified. Here we report the simultaneous observation of these two phenomena in an organic chiral superconductor by magnetoresistance measurements in the vicinity of the superconducting transition temperature. A pair of oppositely polarized spins is demonstrated by spatially mapping the spin polarity in an electric alternating current excitation. The obtained spin polarization exceeds that of the Edelstein effect(6-10) by several orders of magnitude, which indicates an effective enhancement of the spin-orbit interaction. Our results demonstrate a solid-state analogue of spin accumulations assumed for chiral molecules, and may provide clues to the origin of their molecular counterparts. In addition, the innovative capability of spin-current sourcing will invigorate superconducting spintronics research(11).