| 研究課題/領域番号 |
22H01923
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| 配分区分 | 補助金 |
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| 研究機関 | 北海道大学 |
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研究代表者 |
Pin Christophe 北海道大学, 電子科学研究所, 特任助教 (50793767)
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| 研究期間 (年度) |
2022-04-01 – 2025-03-31
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| キーワード | plasmonics / nanogap / chirality / enantioselectivity / hot electron |
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| 研究実績の概要 |
An analytical model was developed to calculate the spatial distribution of the spin and orbital momentum carried by the electric field near the center of the nanogap of a plasmonic trimer nanoantenna excited either by a Gaussian laser beam or by an optical vortex laser beam. Theoretical analysis based on those results were used to discuss the experimental results obtained by my collaborator Dr. A.-C. Cheng. This work was published earlier this year in the scientific journal Small.
In parallel, numerical simulations were conducted to design plasmonic nanogap antennas that enable orbital angular momentum conversion between the incident light and the electric field in the vicinity of the nanogap. Especially, I designed both resonant and non-resonant antennas that enable the generation of optical nanovortex when irradiated by a circularly polarized plane wave. Those results have been presented at an international conference and some results have been submitted to the conference proceedings. A manuscript is under preparation to submit an article to a peer-reviewed scientific journal.
Based on those previous results, the chiral properties of the electric field in the vicinity of a plasmonic nanogap antenna have been investigated further. Especially, I numerically demonstrated the existence of nanoscale skyrmion patterns in the spin angular momentum texture of the electric field near the nanogap of plasmonic multimer antenna irradiated by a circularly polarized plane wave. This result may lead to new techniques to optically generate or control magnetic spin skyrmions.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
3: やや遅れている
理由
Due to some difficulties in the fabrication of gold nanostructures with a chiral nanogap and in the spectroscopic measurement of the fluorescence emission of chiral fluorophores, new directions are being investigated to explore chiral light-matter interactions using plasmonic nanogap antennas. Some results about the spin and orbital angular momentum of the nanogap electric field have been published, and another research article is under preparation to report on the design of plasmonic multimer antennas that enable the generation of optical nanovortex when irradiated by a circularly polarized plane wave.
Due to my recent move from Hokkaido University to the Okinawa Institute of Science and Technology, a new experimental setup is currently under construction.
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| 今後の研究の推進方策 |
Further experiments will be performed to investigate the fabrication of gold nanostructures with a chiral nanogap on a silicon substrate. Plasmonic nanogap antenna that enable the generation of optical nanovortex when irradiated by a circularly polarized plane wave will be also fabricated and, if possible, characterized by near-field optical microscopy technique. However, during the upcoming year, the fabrication of gold nanostructures by electron-beam lithography may require further usage of the cleanroom facility of the Research Institute for Electronic Science in Hokkaido University.
Spectroscopic measurements of the fluorescence properties of chiral fluorophores will be also further investigated.
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