Using the Gorkov equations, we provide an exact solution for a one-dimensional model of superconductivity in the presence of a conical helicoidal exchange field. Due to the special type of symmetry of the system, the superconducting transition always occurs into a nonuniform superconducting phase (in contrast with the Fulde-Ferrell-Larkin-Ovchinnikov state, which appears only at low temperatures). We directly demonstrate that the uniform superconducting state in our model carries a current and thus does not correspond to the ground state. We study in the framework of the Bogoliubov-de Gennes approach the properties of the Josephson junction with a conical ferromagnet as a weak link. In our numerical calculations, we do not use any approximations (such as, e.g., a quasiclassical approach), and we show a realization of an anomalous $ϕ_{0}$ junction (with a spontaneous phase difference $ϕ_{0}$ in the ground state). The spontaneous phase difference $ϕ_{0}$ strongly increases at high values of the exchange field near the borderline with a half-metal, and it exists also in the half-metal regime.
Theory of superconducting and magnetic proximity effect in S$\mid$F structures with inhomogeneous magnetization textures and spin-active interfaces
我们研究了超导体$\mid$铁磁双层中的邻近效应和逆邻近效应，并考虑了迄今为止文献中大多被忽视的几个重要因素。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，这两者都预计将存在于真实的实验样品。我们的方法是数值，使我们能够访问完整的邻近效应制度。在第一部分中，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。我们在第一部分中的两个主要结果是布洛赫和内尔畴壁如何影响邻近诱导的超导关联的研究和研究的超导邻近效应在锥形铁磁体。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。在这项工作的第二部分中，我们调查的逆邻近效应，强调在超导区域的感应磁化强度的结果的“泄漏”的铁磁区域。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，导致在超导区域与\textit{the same sign}在邻近铁磁体的感应磁化。
Ni-Ga bilayers are a versatile platform for exploring the competition between strongly antagonistic ferromagnetic and superconducting phases. We characterize the impact of this competition on the transport properties of highly-ballistic Al/Al2O3(/EuS)/Ni-Ga tunnel junctions from both experimental and theoretical points of view. While the conductance spectra of junctions comprising Ni (3 nm)-Ga (60 nm) bilayers can be well understood within the framework of earlier results, which associate the emerging main conductance maxima with the junction films' superconducting gaps, thinner Ni (1.6 nm)-Ga…
