Phonon localization in nanowires dominated by surface roughness

Studies of possible localization of phonons in nanomaterials have gained importance in recent years in the context of thermoelectricity where phonon-localization can reduce thermal conductivity, thereby improving the efficiency of thermoelectric devices. However, despite significant efforts, phonon-...

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Bibliographic Details
Published in:Physical review. B 2019-04, Vol.99 (13), p.134208, Article 134208
Main Authors: Markoš, P., Muttalib, K. A.
Format: Article
Language:English
Subjects:
Localization
Nanomaterials
Nanowires
Phonons
Surface roughness
Thermal conductivity
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Summary:Studies of possible localization of phonons in nanomaterials have gained importance in recent years in the context of thermoelectricity where phonon-localization can reduce thermal conductivity, thereby improving the efficiency of thermoelectric devices. However, despite significant efforts, phonon-localization has not yet been observed experimentally in real materials. Here we propose that surface-roughness dominated nanowires are ideal candidates to observe localization of phonons, and show numerically that the space and time evolution of the energy generated by a heat-pulse injected at a given point shows clear signatures of phonon localization. We suggest that the same configuration might allow experimental observation of localization of phonons. Our results confirm the universality in the surface-roughness dominated regime proposed earlier, which allows us to characterize the strength of disorder by a single parameter combining the width of the wire as well as the mean height of the corrugation and its correlation length.
ISSN:2469-9950
2469-9969
DOI:10.1103/PhysRevB.99.134208