Pub Date : 2018-11-06DOI: 10.5772/INTECHOPEN.81292
K. Sasaoka, Takahiro Yamamoto
We give a theoretical review of recent development of the mesoscopic physics of phonon transport in carbon nanotubes, including the quantization of phonon thermal conductance, phonon Anderson localization, and so on. A single-walled carbon nanotube (SWCNT) can be regarded as a typical one-dimensional phonon conductor and exhibits various interesting phenomena originating from its one dimensionality. For example, a pristine SWCNT with- out any defects shows the quantization of phonon thermal conductance at low temperature. On the other hand, a defective SWCNT with randomly distributed carbon isotopes shows the phonon Anderson localization originating from the interference between phonons scattered by isotope impurities.
{"title":"Mesoscopic Physics of Phonon Transport in Carbon Materials","authors":"K. Sasaoka, Takahiro Yamamoto","doi":"10.5772/INTECHOPEN.81292","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.81292","url":null,"abstract":"We give a theoretical review of recent development of the mesoscopic physics of phonon transport in carbon nanotubes, including the quantization of phonon thermal conductance, phonon Anderson localization, and so on. A single-walled carbon nanotube (SWCNT) can be regarded as a typical one-dimensional phonon conductor and exhibits various interesting phenomena originating from its one dimensionality. For example, a pristine SWCNT with- out any defects shows the quantization of phonon thermal conductance at low temperature. On the other hand, a defective SWCNT with randomly distributed carbon isotopes shows the phonon Anderson localization originating from the interference between phonons scattered by isotope impurities.","PeriodicalId":297371,"journal":{"name":"Phonons in Low Dimensional Structures","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132210623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-11-05DOI: 10.5772/INTECHOPEN.77237
P. Deymier, J. Vasseur, K. Runge, P. Lucas
We show that the directional projection of longitudinal waves propagating in a parallel array of N elastically coupled waveguides can be described by a nonlinear Dirac-like equation in a 2 N dimensional exponential space. This space spans the tensor product Hilbert space of the two-dimensional subspaces of N uncoupled waveguides grounded elastically to a rigid substrate (called φ -bits). The superposition of directional states of a φ -bit is analogous to that of a quantum spin. We can construct tensor product states of the elastically coupled system that are nonseparable on the basis of tensor product states of N φ -bits. We propose a system of coupled waveguides in a ring configuration that supports these nonseparable states.
{"title":"Separability and Nonseparability of Elastic States in Arrays of One-Dimensional Elastic Waveguides","authors":"P. Deymier, J. Vasseur, K. Runge, P. Lucas","doi":"10.5772/INTECHOPEN.77237","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.77237","url":null,"abstract":"We show that the directional projection of longitudinal waves propagating in a parallel array of N elastically coupled waveguides can be described by a nonlinear Dirac-like equation in a 2 N dimensional exponential space. This space spans the tensor product Hilbert space of the two-dimensional subspaces of N uncoupled waveguides grounded elastically to a rigid substrate (called φ -bits). The superposition of directional states of a φ -bit is analogous to that of a quantum spin. We can construct tensor product states of the elastically coupled system that are nonseparable on the basis of tensor product states of N φ -bits. We propose a system of coupled waveguides in a ring configuration that supports these nonseparable states.","PeriodicalId":297371,"journal":{"name":"Phonons in Low Dimensional Structures","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129411890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-11-05DOI: 10.5772/INTECHOPEN.80447
R. Iotti, F. Rossi
Electron-phonon interaction is a key mechanism for charge and heat transport in both bulk materials as well as in state-of-the-art electronic and optoelectronic solid-state devices. Indeed, that of an effective heat dissipation, at the diverse design levels, has always been a primary issue in device operation and performances. In various circumstances, the charge carrier subsystem happens to be coupled to a significant nonequilibrium optical phonon population. This regime may be particularly pronounced in new-generation quantum emitters based on semiconductor heterostructures and operating both in the mid- infrared as well as in the terahertz region of the electromagnetic spectrum. In this chapter, we review a global kinetic approach based on a Monte Carlo simulation technique that we have recently proposed for the modeling of the combined carrier-phonon nonequilibrium dynamics in realistic unipolar multisubband device designs. Results for the case of a pro- totypical resonant-phonon terahertz emitting quantum cascade laser are shown and discussed.
{"title":"Monte Carlo Kinetic Modeling of the Combined Carrier-Phonon Nonequilibrium Dynamics in Semiconductor Heterostructure Devices","authors":"R. Iotti, F. Rossi","doi":"10.5772/INTECHOPEN.80447","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.80447","url":null,"abstract":"Electron-phonon interaction is a key mechanism for charge and heat transport in both bulk materials as well as in state-of-the-art electronic and optoelectronic solid-state devices. Indeed, that of an effective heat dissipation, at the diverse design levels, has always been a primary issue in device operation and performances. In various circumstances, the charge carrier subsystem happens to be coupled to a significant nonequilibrium optical phonon population. This regime may be particularly pronounced in new-generation quantum emitters based on semiconductor heterostructures and operating both in the mid- infrared as well as in the terahertz region of the electromagnetic spectrum. In this chapter, we review a global kinetic approach based on a Monte Carlo simulation technique that we have recently proposed for the modeling of the combined carrier-phonon nonequilibrium dynamics in realistic unipolar multisubband device designs. Results for the case of a pro- totypical resonant-phonon terahertz emitting quantum cascade laser are shown and discussed.","PeriodicalId":297371,"journal":{"name":"Phonons in Low Dimensional Structures","volume":"140 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131918204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-11-05DOI: 10.5772/INTECHOPEN.78584
Bao Jing-fu, Muhammad Ammar Khan, Bao Feihong
In this chapter we present the theory of phononic crystal, classification of PnC according to its physical nature, and phononic crystal (PnC) phenomena in locally resonant materials with 2D, and 3D crystals structure. In this chapter, phononic crystal (PnC) micro-electro mechanical system (MEMS) resonators with different transduction schemes such as electro-statically, piezoresistively, piezoelectrically transduced MEMS resonators are explained. In this chapter, we employed phononic crystal strip in MEMS resonators is explained to reduce anchor loss, and analysis of eigen frequency mode of the resonators. The phononic crystal strip with supporting tethers is designed to see the formation of band gap by introducing square holes, and improvement of quality factor and harmonic response. We show that holes can help to reduce the static mass of PnC strip tether without affecting on band gaps.
{"title":"Phononic Crystal Resonators","authors":"Bao Jing-fu, Muhammad Ammar Khan, Bao Feihong","doi":"10.5772/INTECHOPEN.78584","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.78584","url":null,"abstract":"In this chapter we present the theory of phononic crystal, classification of PnC according to its physical nature, and phononic crystal (PnC) phenomena in locally resonant materials with 2D, and 3D crystals structure. In this chapter, phononic crystal (PnC) micro-electro mechanical system (MEMS) resonators with different transduction schemes such as electro-statically, piezoresistively, piezoelectrically transduced MEMS resonators are explained. In this chapter, we employed phononic crystal strip in MEMS resonators is explained to reduce anchor loss, and analysis of eigen frequency mode of the resonators. The phononic crystal strip with supporting tethers is designed to see the formation of band gap by introducing square holes, and improvement of quality factor and harmonic response. We show that holes can help to reduce the static mass of PnC strip tether without affecting on band gaps.","PeriodicalId":297371,"journal":{"name":"Phonons in Low Dimensional Structures","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123876171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-04-19DOI: 10.5772/INTECHOPEN.78231
D. Sekyi-Arthur, S. Mensah, N. G. Mensah, K. Dompreh, R. Edziah
We studied theoretically the absorption of acoustic phonons in the hypersound regime in Fluorine modified Carbon Nanotube (F-CNT) $Gamma_q^{F-CNT}$ and compared it to that of undoped Single Walled Nanotube (SWNT) $Gamma_q^{SWNT}$. Per the numerical analysis, the F-CNT showed less absorption to that of SWNT thus $vertGamma_q^{F-CNT}vert < vertGamma_q^{SWNT}vert $. This is due to the fact that Fluorine is highly electronegative and weakens the walls of the SWNT. Thus, the $pi$-electrons associated with to the Fluorine which causes less free charge carriers to interact with the phonons and hence changing the metallic properties of the SWNT to semiconductor by the doping process. From the graphs obtained, the ratio of hypersound absorption in SWNT to F-CNT at $T = 45K$ is $frac{Gamma_{(SWNT)}}{Gamma_{(F-CNT)}}approx 29$ whilst at $T = 55K$, is $frac{Gamma_{(SWNT)}}{Gamma_{(F-CNT)}}approx 9$ and at $T = 65K$, is $frac{Gamma_{(SWNT)}}{Gamma_{(F-CNT)}}approx 2$. Clearly, the ratio decreases as the temperature increases.
{"title":"Absorption of Acoustic Phonons in Fluorinated Carbon Nanotubes with Non-Parabolic, Double Periodic Band","authors":"D. Sekyi-Arthur, S. Mensah, N. G. Mensah, K. Dompreh, R. Edziah","doi":"10.5772/INTECHOPEN.78231","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.78231","url":null,"abstract":"We studied theoretically the absorption of acoustic phonons in the hypersound regime in Fluorine modified Carbon Nanotube (F-CNT) $Gamma_q^{F-CNT}$ and compared it to that of undoped Single Walled Nanotube (SWNT) $Gamma_q^{SWNT}$. Per the numerical analysis, the F-CNT showed less absorption to that of SWNT thus $vertGamma_q^{F-CNT}vert < vertGamma_q^{SWNT}vert $. This is due to the fact that Fluorine is highly electronegative and weakens the walls of the SWNT. Thus, the $pi$-electrons associated with to the Fluorine which causes less free charge carriers to interact with the phonons and hence changing the metallic properties of the SWNT to semiconductor by the doping process. From the graphs obtained, the ratio of hypersound absorption in SWNT to F-CNT at $T = 45K$ is $frac{Gamma_{(SWNT)}}{Gamma_{(F-CNT)}}approx 29$ whilst at $T = 55K$, is $frac{Gamma_{(SWNT)}}{Gamma_{(F-CNT)}}approx 9$ and at $T = 65K$, is $frac{Gamma_{(SWNT)}}{Gamma_{(F-CNT)}}approx 2$. Clearly, the ratio decreases as the temperature increases.","PeriodicalId":297371,"journal":{"name":"Phonons in Low Dimensional Structures","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114821222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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