Optomechanical resonators based on low dimensional materials
Mechanical resonators based on low dimensional materials have attracted a lot of attention due to their remarkable properties. Their ultra-low mass and high Q factors make them exceptional sensors, offering new possibilities in the studies of the material strength and the thermodynamic properties of...
| Autor: | |
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2021 |
| País: | España |
| Institución: | CBUC, CESCA |
| Repositorio: | TDR. Tesis Doctorales en Red |
| OAI Identifier: | oai:www.tdx.cat:10803/673883 |
| Acceso en línea: | http://hdl.handle.net/10803/673883 https://dx.doi.org/10.5821/dissertation-2117-364849 |
| Access Level: | acceso abierto |
| Palabra clave: | Àrees temàtiques de la UPC::Física 535 |
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Optomechanical resonators based on low dimensional materials |
| title |
Optomechanical resonators based on low dimensional materials |
| spellingShingle |
Optomechanical resonators based on low dimensional materials Tepsic, Slaven Àrees temàtiques de la UPC::Física 535 |
| title_short |
Optomechanical resonators based on low dimensional materials |
| title_full |
Optomechanical resonators based on low dimensional materials |
| title_fullStr |
Optomechanical resonators based on low dimensional materials |
| title_full_unstemmed |
Optomechanical resonators based on low dimensional materials |
| title_sort |
Optomechanical resonators based on low dimensional materials |
| dc.creator.none.fl_str_mv |
Tepsic, Slaven |
| author |
Tepsic, Slaven |
| author_facet |
Tepsic, Slaven |
| author_role |
author |
| dc.contributor.none.fl_str_mv |
Bachtold, Adrian Universitat Politècnica de Catalunya. Institut de Ciències Fotòniques |
| dc.subject.none.fl_str_mv |
Àrees temàtiques de la UPC::Física 535 |
| topic |
Àrees temàtiques de la UPC::Física 535 |
| description |
Mechanical resonators based on low dimensional materials have attracted a lot of attention due to their remarkable properties. Their ultra-low mass and high Q factors make them exceptional sensors, offering new possibilities in the studies of the material strength and the thermodynamic properties of low dimensional materials. The goal of this thesis is to shed light on the thermal and elastic properties of low dimensional materials across a wide temperature range. The first part of the thesis is focused on the study of the temperature dependence of the stiffness of carbon nanotubes. By measuring the resonance frequency of singly clamped carbon nanotube resonators as a function of temperature, we can obtain information on the Young’s modulus of the measured carbon nanotubes. We observe a relative shift of the Young’s modulus over a large temperature range with a slope of -(173 +/- 65) ppm/K, consistent with two different theoretical models based on the thermal dynamics of the lattice. The results show the dependence of the fundamental mechanical mode on the phonons in carbon nanotubes via the Young’s modulus. The measured data also indicates the coupling between mechanical modes and the phonon thermal bath in nanotubes. The phonon thermal bath in our experiments likely operates in the Akhiezer limit. In the second part of the thesis, we present the temperature dependence of the thermal conductivity and the specific heat capacity in the MoSe2 monolayer in a larger temperature range. Both the thermal conductivity and the specific heat capacity measurements are consistent with predictions based on first-principles. The results show that the phonon transport in a MoSe2 monolayer can be both diffusive and ballistic, depending on the temperature of the monolayer. The method used in this measurement can be used to investigate the thermal properties of many two-dimensional materials. Furthermore, it opens the possibility to investigate interesting thermal transport regimes in two-dimensional materials like hydro-dynamic regime or anomalous heat conduction. |
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2021 |
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2021 2022 2022 |
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info:eu-repo/semantics/doctoralThesis info:eu-repo/semantics/publishedVersion |
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doctoralThesis |
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http://hdl.handle.net/10803/673883 https://dx.doi.org/10.5821/dissertation-2117-364849 |
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http://hdl.handle.net/10803/673883 https://dx.doi.org/10.5821/dissertation-2117-364849 |
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Inglés |
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Inglés |
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http://creativecommons.org/licenses/by-nc-sa/4.0/ info:eu-repo/semantics/openAccess |
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http://creativecommons.org/licenses/by-nc-sa/4.0/ |
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openAccess |
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122 p. application/pdf application/pdf |
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Universitat Politècnica de Catalunya |
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Universitat Politècnica de Catalunya |
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TDX (Tesis Doctorals en Xarxa) reponame:TDR. Tesis Doctorales en Red instname:CBUC, CESCA |
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CBUC, CESCA |
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TDR. Tesis Doctorales en Red |
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TDR. Tesis Doctorales en Red |
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1869408995063627776 |
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Optomechanical resonators based on low dimensional materialsTepsic, SlavenÀrees temàtiques de la UPC::Física535Mechanical resonators based on low dimensional materials have attracted a lot of attention due to their remarkable properties. Their ultra-low mass and high Q factors make them exceptional sensors, offering new possibilities in the studies of the material strength and the thermodynamic properties of low dimensional materials. The goal of this thesis is to shed light on the thermal and elastic properties of low dimensional materials across a wide temperature range. The first part of the thesis is focused on the study of the temperature dependence of the stiffness of carbon nanotubes. By measuring the resonance frequency of singly clamped carbon nanotube resonators as a function of temperature, we can obtain information on the Young’s modulus of the measured carbon nanotubes. We observe a relative shift of the Young’s modulus over a large temperature range with a slope of -(173 +/- 65) ppm/K, consistent with two different theoretical models based on the thermal dynamics of the lattice. The results show the dependence of the fundamental mechanical mode on the phonons in carbon nanotubes via the Young’s modulus. The measured data also indicates the coupling between mechanical modes and the phonon thermal bath in nanotubes. The phonon thermal bath in our experiments likely operates in the Akhiezer limit. In the second part of the thesis, we present the temperature dependence of the thermal conductivity and the specific heat capacity in the MoSe2 monolayer in a larger temperature range. Both the thermal conductivity and the specific heat capacity measurements are consistent with predictions based on first-principles. The results show that the phonon transport in a MoSe2 monolayer can be both diffusive and ballistic, depending on the temperature of the monolayer. The method used in this measurement can be used to investigate the thermal properties of many two-dimensional materials. Furthermore, it opens the possibility to investigate interesting thermal transport regimes in two-dimensional materials like hydro-dynamic regime or anomalous heat conduction.Los resonadores mecánicos basados en materiales de baja dimensionalidad han llamado la atención de la comunidad científica debido a sus singulares propiedades. Su pequeña masa y sus altos factores de calidad (Q) los convierten en sensores excepcionales, ofreciendo un nuevo abanico de posibilidades en el estudio de las propiedades mecánicas y termodinamicas de los materiales de baja dimensionalidad. El objetivo de ésta tesis es el estudio de las propiedades térmicas y elásticas de los materiales de baja dimensionalidad en un amplio rango de temperaturas. La primera parte de la tesis se centra en la evolución de la rigidez de los nanotubo de carbono en función de la temperatura. La medida de la frecuencia de resonancia de un resonador basado en un nanotubos de carbono con un único punto de anclaje en función de la temperatura, ofrece información sobre el módulo de Young de dicho nanotubo. Observamos un cambio relativo del módulo de Young en un amplio rango de temperaturas con una pendiente de -(173 +/- 65) ppm/K, en acuerdo con dos modelos teóricos diferentes basados en la dinámica térmica de la red cristalina del material. Los resultados muestran la influencia de los fonones del nanotubo de carbono en el modo mecánico fundamental a través del módulo de Young. Los datos también indican el acoplamiento entre los modos mecánicos y el baño térmico de fonones en los nanotubos. Es probable que el baño térmico de fonones en nuestros experimentos opere en el límite de Akhiezer. En la segunda parte de la tesis, presentamos la evolución de la conductividad térmica y la capacidad calorífica específica de una monocapa MoSe2 en función de la temperatura para un rango más amplio. Tanto la conductividad térmica como las medidas de la capacidad calorífica específica concuerdan con las predicciones basadas en los primeros principios. Los resultados muestran que el transporte de fonones en la monocapa MoSe2 puede ser difusivo o balístico, dependiendo de la temperatura de dicha monocapa. El método utilizado en esta medida se puede utilizar para investigar las propiedades térmicas de muchos materiales bidimensionales. Asimismo, abre la posibilidad de investigar distintos regímenes de transporte térmico en materiales bidimensionales cómo el régimen hidrodinámico o la conducción de calor anómala.DOCTORAT EN FOTÒNICA (Pla 2013)Universitat Politècnica de CatalunyaBachtold, AdrianUniversitat Politècnica de Catalunya. Institut de Ciències Fotòniques202220222021info:eu-repo/semantics/doctoralThesisinfo:eu-repo/semantics/publishedVersion122 p.application/pdfapplication/pdfhttp://hdl.handle.net/10803/673883https://dx.doi.org/10.5821/dissertation-2117-364849TDX (Tesis Doctorals en Xarxa)reponame:TDR. Tesis Doctorales en Redinstname:CBUC, CESCAInglésL'accés als continguts d'aquesta tesi queda condicionat a l'acceptació de les condicions d'ús establertes per la següent llicència Creative Commons: http://creativecommons.org/licenses/by-nc-sa/4.0/http://creativecommons.org/licenses/by-nc-sa/4.0/info:eu-repo/semantics/openAccessoai:www.tdx.cat:10803/6738832026-06-14T12:46:07Z |
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