Coupling of two superconductors through a ferromagnet:: Evidence for a π junction
Coupling of two superconductors through a ferromagnet:: Evidence for a π junction
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DOI：
10.1103/physrevlett.86.2427
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发表时间：
2001-03-12
影响因子：
8.6
通讯作者：
Aarts, J
中科院分区：
文献类型：
--
作者：
Ryazanov, VV;Oboznov, VA;Aarts, J
我们报告了在约瑟夫森结中临界电流I-c的温度依赖性的测量结果，该结由传统的超导Nb层和CuxNi1-x合金的弱铁磁性夹层组成，x约为0.5。随着温度的降低，I-c一般会增加，但对于特定厚度的铁磁夹层，I-c会出现最大值，然后急剧下降至零，之后I-c再次上升。如此尖锐的尖峰只能通过假设结在高温下从0相状态转变为低温下的pi相状态来解释。
We report measurements of the temperature dependence of the critical current, I-c, in Josephson junctions consisting of conventional superconducting banks of Nb and a weakly ferromagnetic interlayer of a CuxNi1-x alloy, with x around 0.5. With decreasing temperature I-c generally increases,but for specific thicknesses of the ferromagnetic interlayer, a maximum is found followed by a strong decrease down to zero, after which I-c rises again. Such a sharp cusp can be explained only by assuming that the junction changes from a 0-phase state at high temperatures to a pi phase state at low temperatures.