Jeon Kun-Rok, Cho Kyungjune, Chakraborty Anirban, Jeon Jae-Chun, Yoon Jiho, Han Hyeon, Kim Jae-Keun, Parkin Stuart S P
Max Planck Institute of Microstructure Physics, Weinberg 2, 06120 Halle (Saale), Germany.
ACS Nano. 2021 Oct 26;15(10):16819-16827. doi: 10.1021/acsnano.1c07192. Epub 2021 Oct 1.
Nonequilibrium studies of two-dimensional (2D) superconductors (SCs) with Ising spin-orbit coupling are prerequisite for their successful application to equilibrium spin-triplet Cooper pairs and, potentially, Majorana Fermions. By taking advantage of the recent discoveries of 2D SCs and their compatibility with any other materials, we fabricate here nonlocal magnon devices to examine how such 2D Ising superconductivity affects the conversion efficiency of magnon spin to quasiparticle charge in superconducting flakes of 2H-NbSe transferred onto ferrimagnetic insulating YFeO. Comparison with a reference device based on a conventionally paired superconductor shows that the YFeO-induced in-plane (IP) exchange spin-splitting in the NbSe flake is hindered by its inherent out-of-plane (OOP) spin-orbit field, which, in turn, limits the transition-state enhancement of the spin-to-charge conversion efficiency. Our out-of-equilibrium study highlights the significance of symmetry matching between underlying Cooper pairs and exchange-induced spin-splitting for the giant transition-state spin-to-charge conversion and may have implications toward proximity-engineered spin-polarized triplet pairing via tuning the relative strength of IP exchange and OOP spin-orbit fields in ferromagnetic insulator/2D Ising SC bilayers.
对具有伊辛自旋轨道耦合的二维（2D）超导体（SCs）进行非平衡研究，是它们成功应用于平衡自旋三重态库珀对以及潜在的马约拉纳费米子的前提条件。借助二维超导体的最新发现及其与任何其他材料的兼容性，我们在此制造了非局部磁振子器件，以研究这种二维伊辛超导性如何影响转移到亚铁磁性绝缘体YFeO上的2H-NbSe超导薄片中磁振子自旋到准粒子电荷的转换效率。与基于常规配对超导体的参考器件的比较表明，NbSe薄片中YFeO诱导的面内（IP）交换自旋分裂受到其固有的面外（OOP）自旋轨道场的阻碍，这反过来又限制了自旋到电荷转换效率的过渡态增强。我们的非平衡研究突出了潜在库珀对与交换诱导的自旋分裂之间对称性匹配对于巨大的过渡态自旋到电荷转换的重要性，并且可能通过调整铁磁绝缘体/二维伊辛超导双层中面内交换和面外自旋轨道场的相对强度，对近邻工程化的自旋极化三重态配对产生影响。
