Impact of interface stiffness in surface-wave resonances on nanostrip-attached substrates
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Abstract
Ogi H., Masuda S., Nagakubo A., et al. Physical Review B, 93(2), 024112, 2016. Copyright 2016 by the American Physical Society.
Surface waves are often excited by interdigitated transducers consisting of many nanostrips attached on a substrate, and it has been recognized that the mass and stiffness of the attached nanostrips affect surface-wave resonances to some extent. Here, we reveal the more noticeable influence of the interfacial stiffness between strips and substrate at high frequencies. This influence is confirmed by exciting and detecting surface-wave resonances up to ∼6 GHz by picosecond ultrasound spectroscopy. The resonance frequency significantly decreases and attenuation increases as the interfacial stiffness decreases for silicon substrate. However, low-attenuation branches appear along the Rayleigh-wave-resonance dispersion curve for silica substrate, and the resonance frequencies remain nearly identical to those of the Rayleigh waves. Previous models fail to reproduce these surface-wave resonance behaviors. The proposed theoretical model, involving the interfacial stiffness, consistently explained them, indicating the importance of the interface bond strength in designing surface-wave resonators.
Journal
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- Physical Review B
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Physical Review B 93 (2), 024112-1-024112-6, 2016-01-22
American Physical Society
