Lifetimes of Confined Acoustic Phonons in Ultrathin Silicon Membranes
Name
Cuffe-2013-Lifetimes of Confined Acoustic Phonons in Ultrathin Silicon Membranes.pdf
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519.5 KB
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Checksum (MD5)
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Author(s)
Cuffe, John
Ristow, O.
Chavez, E.
Shchepetov, A.
Chapuis, P. O.
Alzina, F.
Hettich, M.
Prunnila, M.
Ahopelto, Jouni
Dekorsy, T.
Date Issued
February 2013
Journal
Physical Review Letters
Publisher
American Physical Society
Citation
Cuffe, J. et al. “Lifetimes of Confined Acoustic Phonons in Ultrathin Silicon Membranes.” Physical Review Letters 110.9 (2013). ©2013 American Physical Society
Version
Final published version
Abstract
We study the relaxation of coherent acoustic phonon modes with frequencies up to 500 GHz in ultrathin free-standing silicon membranes. Using an ultrafast pump-probe technique of asynchronous optical sampling, we observe that the decay time of the first-order dilatational mode decreases significantly from ∼4.7 ns to 5 ps with decreasing membrane thickness from ∼194 to 8 nm. The experimental results are compared with theories considering both intrinsic phonon-phonon interactions and extrinsic surface roughness scattering including a wavelength-dependent specularity. Our results provide insight to understand some of the limits of nanomechanical resonators and thermal transport in nanostructures.
MIT Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
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Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.1103/PhysRevLett.110.095503
