Ojajärvi Risto, Bergeret F S, Silaev M A, Heikkilä Tero T
Department of Physics and Nanoscience Center, University of Jyväskylä, P.O. Box 35 (YFL), FI-40014 University of Jyväskylä, Finland.
Centro de Física de Materiales (CFM-MPC), Centro Mixto CSIC-UPV/EHU, Manuel de Lardizabal 5, E-20018 San Sebastián, Spain.
Phys Rev Lett. 2022 Apr 22;128(16):167701. doi: 10.1103/PhysRevLett.128.167701.
A conventional superconductor sandwiched between two ferromagnets can maintain coherent equilibrium spin current. This spin supercurrent results from the rotation of odd-frequency spin correlations induced in the superconductor by the magnetic proximity effect. In the absence of intrinsic magnetization, the superconductor cannot maintain multiple rotations of the triplet component but instead provides a Josephson type weak link for the spin supercurrent. We determine the analog of the current-phase relation in various circumstances and show how it can be accessed in experiments on dynamic magnetization. In particular, concentrating on the magnetic hysteresis and the ferromagnetic resonance response, we show how the spin supercurrent affects the nonequilibrium dynamics of magnetization which depends on a competition between spin supercurrent mediated static exchange contribution and a dynamic spin pumping contribution. Depending on the outcome of this competition, a mode crossing in the system can either be an avoided crossing or mode locking.
夹在两个铁磁体之间的常规超导体可以维持相干平衡自旋电流。这种自旋超电流源于磁近邻效应在超导体中诱导的奇频自旋关联的旋转。在没有固有磁化的情况下，超导体无法维持三重态分量的多次旋转，而是为自旋超电流提供一个约瑟夫森型弱连接。我们确定了各种情况下电流 - 相位关系的类似物，并展示了如何在动态磁化实验中获取它。特别是，专注于磁滞和铁磁共振响应，我们展示了自旋超电流如何影响磁化的非平衡动力学，这取决于自旋超电流介导的静态交换贡献和动态自旋泵浦贡献之间的竞争。根据这种竞争的结果，系统中的模式交叉要么是避免交叉，要么是模式锁定。
