In conventional superconductors, electrons of opposite spins are bound into Cooper pairs. However, when the superconductor is in contact with a non-uniformly ordered ferromagnet, an exotic type of superconductivity can appear at the interface, with electrons bound into three possible spin-triplet states. Triplet pairs with equal spin play a vital role in low-dissipation spintronics. Despite the observation of supercurrents through ferromagnets, spectroscopic evidence for the existence of equal-spin triplet pairs is still missing. Here we show a theoretical model that reveals a characteristic gap structure in the quasiparticle density of states which provides a unique signature for the presence of equal-spin triplet pairs. By scanning tunnelling spectroscopy we measure the local density of states to reveal the spin configuration of triplet pairs. We demonstrate that the Al/EuS interface causes strong and tunable spin-mixing by virtue of its spin-dependent transmission.

中文翻译：

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在 Al/EuS 界面上产生等自旋三重态超导性。

在传统的超导体中，自旋相反的电子被束缚成库珀对。然而，当超导体与非均匀有序的铁磁体接触时，界面处会出现一种奇异的超导性，电子被束缚成三种可能的自旋三重态。具有相等自旋的三重态对在低耗散自旋电子学中发挥着至关重要的作用。尽管通过铁磁体观察到了超电流，但仍然缺乏等自旋三重态对存在的光谱证据。在这里，我们展示了一个理论模型，该模型揭示了准粒子态密度中的特征间隙结构，该结构为等自旋三重态对的存在提供了独特的特征。通过扫描隧道光谱，我们测量局域态密度以揭示三重态对的自旋构型。我们证明 Al/EuS 界面凭借其自旋相关传输而引起强烈且可调节的自旋混合。