Coupled elastic membranes model for quantum heat transport in semiconductor nanowires

Lawn, Julian A., and Kosov, Daniel S. (2019) Coupled elastic membranes model for quantum heat transport in semiconductor nanowires. European Physical Journal B: Condensed Matter and Complex Systems, 92 (2). 43.

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Abstract

Presented here is a nanowire model, consisting of coupled elastic membranes with the purpose of investigating thermal transport in quasi-one-dimensional quantum systems. The vibrations of each elastic membrane are quantized and the flow of the vibrational energy between adjacent membranes is allowed. The ends of the nanowire are attached to thermal baths held at different temperatures. We derived quantum master equation for energy flow across the nanowire and obtained thermal currents and other key observables. We study the effects of a disordered boundary on the thermal current by randomizing the membrane radii. We evaluate the model as a nanowire analogue as well as study the effects of a disordered boundary on thermal conductivity. The calculations show that the membrane lattice model demonstrates diameter phonon confinement and a severe reduction in thermal conductivity due to surface roughness which is characteristic of semiconductor nanowires. The surface roughness also produces a length dependence of the thermal conductivity of the form κ = αLβ, with β dependent on disorder characteristics, in the otherwise ballistic regime. Finally, the parameters of the model are fitted to available experimental data for silicon nanowires and the results of the calculations are assessed against the experimental data.

Item ID: 57232
Item Type: Article (Research - C1)
ISSN: 1434-6036
Keywords: mesoscopic and nanoscale Systems
Copyright Information: © EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature 2019
Date Deposited: 07 Mar 2019 06:44
FoR Codes: 02 PHYSICAL SCIENCES > 0299 Other Physical Sciences > 029999 Physical Sciences not elsewhere classified @ 100%
SEO Codes: 97 EXPANDING KNOWLEDGE > 970102 Expanding Knowledge in the Physical Sciences @ 100%
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