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arXiv · 2412.19267

Anomalous frequency scaling of acoustic phonon damping in nickel cavities fabricated by ps-laser delamination

Alba Viejo-Rodríguez·Andrea Rossetti·Marco Gandolfi·Yoav Urbina-Elgueta·Evgeny B. Modin·Svetlana Starikovskaia·Tat Loon Chng·Vasily Temnov·Maria Antonietta Vincenti·Daniele Brida·Paolo Vavassori·Nicolò Maccaferri
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Abstract

Single-shot picosecond (ps) laser induced delamination allows for the direct generation of suspended membranes from a continuous metallic film, offering a promising platform for control of ultrafast magnetization dynamics driven by acoustic waves. Using the picosecond-ultrasonics method, we demonstrate that long-lived low-frequency acoustic waves can be optically-excited in the delaminated cavities. At the same time, higher-frequency modes >60GHz exhibit a surprisingly fast damping, following a scaling law incompatible with the expected attenuation mediated by phonon-phonon scattering. Comparing measurements between delaminated cavities and a benchmark nickel film in contact with the substrate, we link our findings with structural modifications of the nickel crystal induced by the delamination process.

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Alba Viejo-Rodríguez, Andrea Rossetti, Marco Gandolfi, Yoav Urbina-Elgueta, Evgeny B. Modin, Svetlana Starikovskaia, Tat Loon Chng, Vasily Temnov, Maria Antonietta Vincenti, Daniele Brida, Paolo Vavassori, Nicolò Maccaferri. 2024-12-26. Anomalous frequency scaling of acoustic phonon damping in nickel cavities fabricated by ps-laser delamination. https://doi.org/10.1063/5.0263631

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