Volkov A F, Efetov K B
Theoretische Physik III, Ruhr-Universität Bochum, D-44780 Bochum, Germany.
Phys Rev Lett. 2009 Feb 20;102(7):077002. doi: 10.1103/PhysRevLett.102.077002.
We consider a bilayer consisting of a d-wave layered superconductor and diffusive ferromagnet with a domain wall (DW). The c axis in the superconductor and DW in the ferromagnet are assumed to be perpendicular to the interface. We demonstrate that in such a heterostructure the inhomogeneous exchange field enhances the proximity effect. It is shown that, whereas in the absence of the exchange field the d-wave condensate decays in the normal metal on the mean free path l, the superconductivity penetrates the ferromagnet along the DW over much larger distances. This happens because the presence of the DW results in a generation of an odd-frequency triplet s-wave component of the condensate. The phenomenon discovered here may help to explain a recent experiment on high-temperature superconductor-ferromagnet bilayers.
我们考虑一个由具有畴壁（DW）的d波层状超导体和扩散铁磁体组成的双层结构。假设超导体中的c轴和铁磁体中的DW垂直于界面。我们证明，在这样的异质结构中，不均匀交换场增强了近邻效应。结果表明，在没有交换场的情况下，d波凝聚态在正常金属中以平均自由程l衰减，而超导性沿着DW穿透铁磁体的距离要大得多。之所以会发生这种情况，是因为DW的存在导致凝聚态产生了奇数频率的三重态s波分量。这里发现的现象可能有助于解释最近关于高温超导体 - 铁磁体双层的实验。
