State Key Laboratory of Surface Physics and Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Department of Physics, Fudan University, Shanghai, 200433, China.
Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai, 200433, China.
Sci Rep. 2017 Jul 13;7(1):5332. doi: 10.1038/s41598-017-05634-0.
The applications of spin dynamos, which could potentially power complex nanoscopic devices, have so far been limited owing to their extremely low energy conversion efficiencies. Here, we present a unique plasmonic diabolo cavity (PDC) that dramatically improves the spin rectification signal (enhancement of more than three orders of magnitude) under microwave excitation; further, it enables an energy conversion efficiency of up to 0.69 mV/mW, compared with ~0.27 μV/mW without a PDC. This remarkable improvement arises from the simultaneous enhancement of the microwave electric field (13-fold) and the magnetic field (~195-fold), which cooperate in the spin precession process generates photovoltage (PV) efficiently under ferromagnetic resonance (FMR) conditions. The interplay of the microwave electromagnetic resonance and the ferromagnetic resonance originates from a hybridized mode based on the plasmonic resonance of the diabolo structure and Fabry-Perot-like modes in the PDC. Our work sheds light on how more efficient spin dynamo devices for practical applications could be realized and paves the way for future studies utilizing both artificial and natural magnetism for applications in many disciplines, such as for the design of future efficient wireless energy conversion devices, high frequent resonant spintronic devices, and magnonic metamaterials.
自旋发电机的应用，有望为复杂的纳米设备提供动力，但由于其极低的能量转换效率，其应用受到限制。在这里，我们提出了一种独特的等离子体盘腔（PDC），在微波激发下，自旋整流信号显著增强（增强三个数量级以上）；此外，它能够实现高达0.69 mV/mW 的能量转换效率，而没有 PDC 时则为0.27 μV/mW。这种显著的改进源于微波电场（13 倍）和磁场（195 倍）的同时增强，它们在自旋进动过程中协同作用，在铁磁共振（FMR）条件下有效地产生光电压（PV）。微波电磁共振和铁磁共振的相互作用源于基于 diabolo 结构的等离子体共振和 PDC 中的 Fabry-Perot 样模式的混合模式。我们的工作阐明了如何实现更高效的自旋发电机器件，为未来的研究铺平了道路，这些研究将利用人工和自然磁性来应用于许多领域，例如设计未来高效的无线能量转换器件、高频共振自旋电子器件和磁性超材料。
