Theory of superconducting and magnetic proximity effect in S/F structures with inhomogeneous magnetization textures and spin-active interfaces
Theory of superconducting and magnetic proximity effect in S/F structures with inhomogeneous magnetization textures and spin-active interfaces
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DOI：
10.1103/physrevb.79.054523
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发表时间：
2009-02-01
影响因子：
3.7
通讯作者：
Sudbo, Asle
中科院分区：
文献类型：
--
作者：
Linder, Jacob;Yokoyama, Takehito;Sudbo, Asle
本文研究了平行于铁磁双层结构的超导体中的邻近效应和逆邻近效应，并考虑了文献中迄今为止所忽略的几个重要因素。这些包括自旋相关的界面相移（自旋-DIPS）和非均匀的纹理中的铁磁层的磁化强度，这两者都有望在真实的实验样品中存在。我们的方法是数值，使我们能够访问完整的邻近效应制度。节中第二部分，我们研究了具有非平凡磁织构的非均匀铁磁体中的超导邻近效应和由此产生的局域态密度。我们在SEC的两个主要结果。第二部分研究了布洛赫畴壁和尼尔畴壁对邻近诱导超导关联的影响，并研究了圆锥铁磁体中的超导邻近效应。后一个主题应该是相关的铁磁体何，这是最近在实验中使用，以证明产生和维持长程三重态超导关联的可能性。节中在第三章中，我们研究了由于铁磁区的“漏磁”而引起的超导区的感应磁化强度的逆邻近效应。结果表明，自旋DIPS的存在下修改先前在文献中获得的结论，在超导区域的感应磁化。特别是，我们发现，自旋DIPS可以触发磁化的反屏蔽效应，导致在超导区域中的感应磁化与邻近铁磁体中相同的符号。
We present a study of the proximity effect and the inverse proximity effect in a superconductor parallel to ferromagnet bilayer, taking into account several important factors which mostly have been ignored in the literature so far. These include spin-dependent interfacial phase shifts (spin-DIPS) and inhomogeneous textures of the magnetization in the ferromagnetic layer, both of which are expected to be present in real experimental samples. Our approach is numerical, allowing us to access the full proximity effect regime. In Sec. II of this work, we study the superconducting proximity effect and the resulting local density of states in an inhomogeneous ferromagnet with a nontrivial magnetic texture. Our two main results in Sec. II are a study of how Bloch and Neel domain walls affect the proximity-induced superconducting correlations and a study of the superconducting proximity effect in a conical ferromagnet. The latter topic should be relevant for the ferromagnet Ho, which was recently used in an experiment to demonstrate the possibility to generate and sustain long-range triplet superconducting correlations. In Sec. III of this work, we investigate the inverse proximity effect with emphasis on the induced magnetization in the superconducting region as a result of the "leakage" from the ferromagnetic region. It is shown that the presence of spin-DIPS modifies conclusions obtained previously in the literature with regard to the induced magnetization in the superconducting region. In particular, we find that the spin-DIPS can trigger an antiscreening effect of the magnetization, leading to an induced magnetization in the superconducting region with the same sign as in the proximity ferromagnet.