Qian Jie, Gou Peng, Pan Hong, Zhu Liping, Gui Y S, Hu C-M, An Zhenghua
State Key Laboratory of Surface Physics, Institute of Nanoelectronic Devices and Quantum Computing, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Department of Physics, Fudan University, Shanghai, 200433, China.
Department of Physics and Astronomy, University of Manitoba, Winnipeg, R3T 2N2, Canada.
Sci Rep. 2020 Nov 6;10(1):19240. doi: 10.1038/s41598-020-76090-6.
Metamaterials provide compelling capabilities to manipulate electromagnetic waves beyond the natural materials and can dramatically enhance both their electric and magnetic fields. The enhanced magnetic fields, however, are far less utilized than the electric counterparts, despite their great potential in spintronics. In this work, we propose and experimentally demonstrate a hybrid perfect metamaterial absorbers which combine the artificial metal/insulator/metal (MIM) metamaterial with the natural ferromagnetic material permalloy (Py) and realize remarkably larger spin rectification effect. Magnetic hot spot of the MIM metamaterial improves considerably electromagnetic coupling with spins in the embedded Py stripes. With the whole hybridized structure being optimized based on coupled-mode theory, perfect absorption condition is approached and an approximately 190-fold enhancement of spin-rectifying photovoltage is experimentally demonstrated at the ferromagnetic resonance at 7.1 GHz. Our work provides an innovative solution to harvest microwave energy for spintronic applications, and opens the door to hybridized magnetism from artificial and natural magnetic materials for emergent applications such as efficient optospintronics, magnonic metamaterials and wireless energy transfer.
超材料具有超越天然材料操纵电磁波的强大能力，能够显著增强其电场和磁场。然而，尽管增强的磁场在自旋电子学中具有巨大潜力，但与电场相比，其利用率却低得多。在这项工作中，我们提出并通过实验证明了一种混合完美超材料吸收体，它将人工金属/绝缘体/金属（MIM）超材料与天然铁磁材料坡莫合金（Py）相结合，并实现了显著更大的自旋整流效应。MIM超材料的磁热点极大地改善了与嵌入Py条纹中自旋的电磁耦合。基于耦合模理论对整个混合结构进行优化，接近完美吸收条件，并在7.1 GHz的铁磁共振下通过实验证明自旋整流光电压提高了约190倍。我们的工作为自旋电子应用中收集微波能量提供了一种创新解决方案，并为人工和天然磁性材料的混合磁性在诸如高效光自旋电子学、磁子超材料和无线能量传输等新兴应用中打开了大门。
