Year: 2025
Type: preprint
Abstract: A key challenge in spintronics is to efficiently generate and manipulate spin current for information processing. Here we study ultrashort spin transport and associated terahertz (THz) emission in a hybrid structure comprising gold nanoparticles, a ferromagnet (FM) and a normal metal (NM) and show that plasmon excitation in the nanoparticles strongly enhances the electron-magnon scattering rate through heating effects, thereby amplifying the spin current generation at the FM$|$NM interface. This effect is even more pronounced when the FM is an insulator with a thickness much smaller than the nanoparticle size. In this case, the gold nanoparticle and NM substrate form a nanocavity with the FM as a dielectric layer, trapping plasmons inside the gap. The resulting spin current can be amplified by two orders of magnitude as compared to the case without plasmon excitations. Our findings provide a novel route to design efficient spintronic THz devices and further open the door to the interdisciplinary field of spintronics and nanophotonics.
Source: arXiv (Cornell University)
Authors: Yuan, H. Y., Duine, Rembert A.
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W6979235382
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