Observation of Spin-Triplet Superconductivity in Co-Based Josephson Junctions
Observation of Spin-Triplet Superconductivity in Co-Based Josephson Junctions
复制标题
DOI：
10.1103/physrevlett.104.137002
复制
发表时间：
2010-04-02
影响因子：
8.6
通讯作者：
Birge, Norman O.
中科院分区：
文献类型：
--
作者：
Khaire, Trupti S.;Khasawneh, Mazin A.;Birge, Norman O.
当我们在Co和两个超导Nb电极之间插入PdNi或CuNi弱铁磁合金薄层时，我们测量了含有Co（强铁磁材料）的约瑟夫森结中的长程超电流。在这样的结的临界电流几乎不衰减的Co厚度在12-28 nm的范围内，而它衰减非常陡峭的类似的结没有合金层。长程超电流是可控的合金层的厚度，达到最大的厚度为几纳米。这些实验观测提供了强有力的证据，诱导自旋三重态对的相关性，这已被预测发生在超导铁磁混合系统中存在的某些类型的磁不均匀性。
We have measured a long-range supercurrent in Josephson junctions containing Co (a strong ferromagnetic material) when we insert thin layers of either PdNi or CuNi weakly ferromagnetic alloys between the Co and the two superconducting Nb electrodes. The critical current in such junctions hardly decays for Co thicknesses in the range of 12-28 nm, whereas it decays very steeply in similar junctions without the alloy layers. The long-range supercurrent is controllable by the thickness of the alloy layer, reaching a maximum for a thickness of a few nm. These experimental observations provide strong evidence for induced spin-triplet pair correlations, which have been predicted to occur in superconducting-ferromagnetic hybrid systems in the presence of certain types of magnetic inhomogeneity.