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arXiv · 2512.02889

Terahertz Emission from Spintronic Stack Nanodecorated with Drop-Cast Core-Shell Plasmonic Nanoparticles

Vittorio Cecconi·Akash Dominic Thomas·Ji Tong Wang·Cheng-Han Lin·Anoop Dhoot·Antonio Cutrona·Abhishek Paul·Luke Peters·Luana Olivieri·Elchin Isgandarov·Juan Sebastian Totero Gongora·Alessia Pasquazi·Marco Peccianti
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Abstract

Spintronic emitters promise to revolutionise terahertz (THz) sources by converting ultrafast optical pulses into broadband THz radiation without phase-matching constraints. Because the conversion relies on spin-current injection across a nanometre-thin magnetic layer, its efficiency is ordinarily limited by weak optical coupling. Here, we present a demonstration of a drop-casting based approach to introduce ultrafast plasmonic-mediated coupling: a sparse-layer of silica-gold core-shell nanoparticles is deposited directly onto a W/Fe/Pt spintronic trilayer. This sparse (six percent) decoration increases the wafer-averaged THz pulse energy, pointing to a very high local conversion enhancement for this low-coverage spintronic emitter compared with the bare stack. This demonstration points to a viable pathway toward highly efficient spintronic terahertz emitters with potential applications in spectroscopy, imaging, and ultrafast technologies.

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Vittorio Cecconi, Akash Dominic Thomas, Ji Tong Wang, Cheng-Han Lin, Anoop Dhoot, Antonio Cutrona, Abhishek Paul, Luke Peters, Luana Olivieri, Elchin Isgandarov, Juan Sebastian Totero Gongora, Alessia Pasquazi, Marco Peccianti. 2025-12-02. Terahertz Emission from Spintronic Stack Nanodecorated with Drop-Cast Core-Shell Plasmonic Nanoparticles. https://arxiv.org/abs/2512.02889

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