论文标题
通过铁磁材料对界面对超电流的影响
Effect of interfaces on supercurrent through ferromagnetic materials
论文作者
论文摘要
铁磁约瑟夫森连接表现出引人入胜的物理和超导逻辑和记忆中应用的潜力。所证明的超导内存原型中的连接包含磁性自旋阀结构，其作为固定层和Nife（Permalloy）作为自由层。但是，Nife表现出较差的超电流传播，这限制了约瑟夫森交界处的效率。我们先前已经表明，通过Cu/Nife/Cu Trilayer的超电流传输可以通过在Cu和Nife之间添加薄层Ni层来改进 - 可能是由于Cu/Ni接口的有利的自旋依赖性传输特性所致。在这项工作中，我们通过用PD/Nife替换CU/Nife接口，进一步探讨了这一想法，PD/Nife也具有更多理想的运输属性。与包含Cu/Nife接口的参考连接相比，新连接率显示出$π$ - 州的超电流增加了2倍，并且第一个$0-π$过渡的位置变化。
Ferromagnetic Josephson junctions exhibit fascinating physics and the potential for applications in superconducting logic and memory. The junctions in a demonstrated superconducting memory prototype contain a magnetic spin-valve structure with Ni as the fixed layer and NiFe (Permalloy) as the free layer. However, NiFe exhibits poor supercurrent transmission, which limits the efficiency of the Josephson junction. We have previously shown that the supercurrent transmission through a Cu/NiFe/Cu trilayer can be improved by adding thin layers of Ni between the Cu and NiFe -- possibly due to the advantageous spin-dependent transport properties of the Cu/Ni interfaces. In this work we explore this idea further by replacing the Cu/NiFe interfaces with Pd/NiFe, which also have more desirable transport properties. Compared to the reference junctions containing Cu/NiFe interfaces, the new junctions exhibit an increase in the $π$-state supercurrent by a factor of 2 along with a change in the position of the first $0-π$ transition.
