Cargando…
Thermal conductance of Nb thin films at sub-kelvin temperatures
We determine the thermal conductance of thin niobium (Nb) wires on a silica substrate in the temperature range of 0.1–0.6 K using electron thermometry based on normal metal-insulator-superconductor tunnel junctions. We find that at 0.6 K, the thermal conductance of Nb is two orders of magnitude lowe...
Autores principales: | , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group
2017
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5290528/ https://www.ncbi.nlm.nih.gov/pubmed/28155895 http://dx.doi.org/10.1038/srep41728 |
_version_ | 1782504649958359040 |
---|---|
author | Feshchenko, A. V. Saira, O.-P. Peltonen, J. T. Pekola, J. P. |
author_facet | Feshchenko, A. V. Saira, O.-P. Peltonen, J. T. Pekola, J. P. |
author_sort | Feshchenko, A. V. |
collection | PubMed |
description | We determine the thermal conductance of thin niobium (Nb) wires on a silica substrate in the temperature range of 0.1–0.6 K using electron thermometry based on normal metal-insulator-superconductor tunnel junctions. We find that at 0.6 K, the thermal conductance of Nb is two orders of magnitude lower than that of Al in the superconducting state, and two orders of magnitude below the Wiedemann-Franz conductance calculated with the normal state resistance of the wire. The measured thermal conductance exceeds the prediction of the Bardeen-Cooper-Schrieffer theory, and demonstrates a power law dependence on temperature as T(4.5), instead of an exponential one. At the same time, we monitor the temperature profile of the substrate along the Nb wire to observe possible overheating of the phonon bath. We show that Nb can be successfully used for thermal insulation in a nanoscale circuit while simultaneously providing an electrical connection. |
format | Online Article Text |
id | pubmed-5290528 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | Nature Publishing Group |
record_format | MEDLINE/PubMed |
spelling | pubmed-52905282017-02-06 Thermal conductance of Nb thin films at sub-kelvin temperatures Feshchenko, A. V. Saira, O.-P. Peltonen, J. T. Pekola, J. P. Sci Rep Article We determine the thermal conductance of thin niobium (Nb) wires on a silica substrate in the temperature range of 0.1–0.6 K using electron thermometry based on normal metal-insulator-superconductor tunnel junctions. We find that at 0.6 K, the thermal conductance of Nb is two orders of magnitude lower than that of Al in the superconducting state, and two orders of magnitude below the Wiedemann-Franz conductance calculated with the normal state resistance of the wire. The measured thermal conductance exceeds the prediction of the Bardeen-Cooper-Schrieffer theory, and demonstrates a power law dependence on temperature as T(4.5), instead of an exponential one. At the same time, we monitor the temperature profile of the substrate along the Nb wire to observe possible overheating of the phonon bath. We show that Nb can be successfully used for thermal insulation in a nanoscale circuit while simultaneously providing an electrical connection. Nature Publishing Group 2017-02-03 /pmc/articles/PMC5290528/ /pubmed/28155895 http://dx.doi.org/10.1038/srep41728 Text en Copyright © 2017, 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 Feshchenko, A. V. Saira, O.-P. Peltonen, J. T. Pekola, J. P. Thermal conductance of Nb thin films at sub-kelvin temperatures |
title | Thermal conductance of Nb thin films at sub-kelvin temperatures |
title_full | Thermal conductance of Nb thin films at sub-kelvin temperatures |
title_fullStr | Thermal conductance of Nb thin films at sub-kelvin temperatures |
title_full_unstemmed | Thermal conductance of Nb thin films at sub-kelvin temperatures |
title_short | Thermal conductance of Nb thin films at sub-kelvin temperatures |
title_sort | thermal conductance of nb thin films at sub-kelvin temperatures |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5290528/ https://www.ncbi.nlm.nih.gov/pubmed/28155895 http://dx.doi.org/10.1038/srep41728 |
work_keys_str_mv | AT feshchenkoav thermalconductanceofnbthinfilmsatsubkelvintemperatures AT sairaop thermalconductanceofnbthinfilmsatsubkelvintemperatures AT peltonenjt thermalconductanceofnbthinfilmsatsubkelvintemperatures AT pekolajp thermalconductanceofnbthinfilmsatsubkelvintemperatures |