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Direct observation of confined acoustic phonon polarization branches in free-standing semiconductor nanowires
Similar to electron waves, the phonon states in semiconductors can undergo changes induced by external boundaries. However, despite strong scientific and practical importance, conclusive experimental evidence of confined acoustic phonon polarization branches in individual free-standing nanostructure...
Autores principales: | , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group
2016
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5109588/ https://www.ncbi.nlm.nih.gov/pubmed/27830698 http://dx.doi.org/10.1038/ncomms13400 |
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author | Kargar, Fariborz Debnath, Bishwajit Kakko, Joona-Pekko Säynätjoki, Antti Lipsanen, Harri Nika, Denis L. Lake, Roger K. Balandin, Alexander A. |
author_facet | Kargar, Fariborz Debnath, Bishwajit Kakko, Joona-Pekko Säynätjoki, Antti Lipsanen, Harri Nika, Denis L. Lake, Roger K. Balandin, Alexander A. |
author_sort | Kargar, Fariborz |
collection | PubMed |
description | Similar to electron waves, the phonon states in semiconductors can undergo changes induced by external boundaries. However, despite strong scientific and practical importance, conclusive experimental evidence of confined acoustic phonon polarization branches in individual free-standing nanostructures is lacking. Here we report results of Brillouin—Mandelstam light scattering spectroscopy, which reveal multiple (up to ten) confined acoustic phonon polarization branches in GaAs nanowires with a diameter as large as 128 nm, at a length scale that exceeds the grey phonon mean-free path in this material by almost an order-of-magnitude. The dispersion modification and energy scaling with diameter in individual nanowires are in excellent agreement with theory. The phonon confinement effects result in a decrease in the phonon group velocity along the nanowire axis and changes in the phonon density of states. The obtained results can lead to more efficient nanoscale control of acoustic phonons, with benefits for nanoelectronic, thermoelectric and spintronic devices. |
format | Online Article Text |
id | pubmed-5109588 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | Nature Publishing Group |
record_format | MEDLINE/PubMed |
spelling | pubmed-51095882017-01-13 Direct observation of confined acoustic phonon polarization branches in free-standing semiconductor nanowires Kargar, Fariborz Debnath, Bishwajit Kakko, Joona-Pekko Säynätjoki, Antti Lipsanen, Harri Nika, Denis L. Lake, Roger K. Balandin, Alexander A. Nat Commun Article Similar to electron waves, the phonon states in semiconductors can undergo changes induced by external boundaries. However, despite strong scientific and practical importance, conclusive experimental evidence of confined acoustic phonon polarization branches in individual free-standing nanostructures is lacking. Here we report results of Brillouin—Mandelstam light scattering spectroscopy, which reveal multiple (up to ten) confined acoustic phonon polarization branches in GaAs nanowires with a diameter as large as 128 nm, at a length scale that exceeds the grey phonon mean-free path in this material by almost an order-of-magnitude. The dispersion modification and energy scaling with diameter in individual nanowires are in excellent agreement with theory. The phonon confinement effects result in a decrease in the phonon group velocity along the nanowire axis and changes in the phonon density of states. The obtained results can lead to more efficient nanoscale control of acoustic phonons, with benefits for nanoelectronic, thermoelectric and spintronic devices. Nature Publishing Group 2016-11-10 /pmc/articles/PMC5109588/ /pubmed/27830698 http://dx.doi.org/10.1038/ncomms13400 Text en Copyright © 2016, The Author(s) http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
spellingShingle | Article Kargar, Fariborz Debnath, Bishwajit Kakko, Joona-Pekko Säynätjoki, Antti Lipsanen, Harri Nika, Denis L. Lake, Roger K. Balandin, Alexander A. Direct observation of confined acoustic phonon polarization branches in free-standing semiconductor nanowires |
title | Direct observation of confined acoustic phonon polarization branches in free-standing semiconductor nanowires |
title_full | Direct observation of confined acoustic phonon polarization branches in free-standing semiconductor nanowires |
title_fullStr | Direct observation of confined acoustic phonon polarization branches in free-standing semiconductor nanowires |
title_full_unstemmed | Direct observation of confined acoustic phonon polarization branches in free-standing semiconductor nanowires |
title_short | Direct observation of confined acoustic phonon polarization branches in free-standing semiconductor nanowires |
title_sort | direct observation of confined acoustic phonon polarization branches in free-standing semiconductor nanowires |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5109588/ https://www.ncbi.nlm.nih.gov/pubmed/27830698 http://dx.doi.org/10.1038/ncomms13400 |
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