Bibliographies thématiques / TeraHertz phonons

Littérature scientifique sur le sujet « TeraHertz phonons »

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Publié le 14 mars 2023

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Articles de revues sur le sujet "TeraHertz phonons"

Renk, K. F., et U. Happek. « Terahertz-phonons : New Phonon Spectroscopies ». Physica Scripta T29 (1 janvier 1989) : 226–29. http://dx.doi.org/10.1088/0031-8949/1989/t29/043.

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Ansari, Meenhaz, Subhana Nafees, S. S. Z. Ashraf et Absar Ahmad. « Terahertz acoustic phonon Cerenkov emission in bilayer graphene ». Journal of Applied Physics 132, n^o 2 (14 juillet 2022) : 024303. http://dx.doi.org/10.1063/5.0091369.

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We present a theoretical investigation on the generation of Cerenkov emission of terahertz acoustic phonons in bilayer graphene (BLG) in the presence of a driving dc electric field. We have numerically and analytically studied the Cerenkov phonon emission spectrum, [Formula: see text], and phonon intensity, [Formula: see text], dependence on the phonon frequency [Formula: see text], drift velocity [Formula: see text], electron temperature [Formula: see text], concentration n, and phonon emission angle [Formula: see text] in BLG with and without considering the chirality of the charge carriers. We find that the magnitude of [Formula: see text] increases at larger drift velocities and applied electric fields with the peak of the spectrum shifting toward the higher frequency side. The spectrum magnitude in BLG is found to be much enhanced as compared to conventional 2D semiconductors and transition metal dichalcogenides, which makes it viable for SASER and other practical device applications. The chiral nature of carriers strongly influences the [Formula: see text] behavior and sharpens the spectrum peak but with a decrease in the magnitude. The chirality favors the negative emission spectrum caused by the absorption of acoustic phonons. [Formula: see text] and [Formula: see text] are found to be strongly dependent on temperature but independent of carrier concentration in the equipartition regime. The study is significant from the point of application of BLG as an acousto/optoelectronic device and high-frequency phonon spectrometers.

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Nika, Denis, Evghenii Pokatilov, Vladimir Fomin, Josef Devreese et Jacques Tempere. « Resonant Terahertz Light Absorption by Virtue of Tunable Hybrid Interface Phonon–Plasmon Modes in Semiconductor Nanoshells ». Applied Sciences 9, n^o 7 (6 avril 2019) : 1442. http://dx.doi.org/10.3390/app9071442.

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Metallic nanoshells have proven to be particularly versatile, with applications in biomedical imaging and surface-enhanced Raman spectroscopy. Here, we theoretically demonstrate that hybrid phonon-plasmon modes in semiconductor nanoshells offer similar advantages in the terahertz regime. We show that, depending on tm,n,nhe doping of the semiconductor shells, terahertz light absorption in these nanostructures can be resonantly enhanced due to the strong coupling between interface plasmons and phonons. A threefold to fourfold increase in the absorption peak intensity was achieved at specific values of electron concentration. Doping, as well as adapting the nanoshell radius, allowed for fine-tuning of the absorption peak frequencies.

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Pavlov, Sergeij G., Heinz Wilhelm Hübers, Nikolay V. Abrosimov et H. Riemann. « Mono- and Polycrystalline Silicon for Terahertz Intracenter Lasers ». Solid State Phenomena 131-133 (octobre 2007) : 579–82. http://dx.doi.org/10.4028/www.scientific.net/ssp.131-133.579.

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The performance of optically pumped terahertz silicon lasers with active media made from mono- and polycrystalline silicon doped by phosphorus has been investigated. The polycrystalline silicon samples consist of grains with a characteristic size distribution in the range from 50 to 500 m. Despite of significant changes of the principal phonon spectrum and increased scattering of phonons at grain boundaries, the silicon laser made from polycrystalline material has a laser threshold and an operation temperature only slightly worse than that of monocrystalline silicon lasers.

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Boldyrev, Kirill N., Boris Z. Malkin et Marina N. Popova. « Magnetic-Field-Tunable Intensity Transfer from Optically Active Phonons to Crystal-Field Excitations in the Reflection Spectra of the PrFe3(BO3)4 Antiferromagnet ». Crystals 12, n^o 3 (14 mars 2022) : 392. http://dx.doi.org/10.3390/cryst12030392.

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We analyze the field-dependent intensities of the coupled electron-phonon modes observed in the low-temperature far-infrared (terahertz) reflection spectra of PrFe3(BO3)4 and develop a theory based on the Green’s function approach. An excellent agreement between the experimental and theoretical data is achieved. The developed theory of the intensity transfer from phonons to quasi-electronic excitations can be applied to the electron-phonon modes in other compounds, in particular, in magnetodielectric materials, where it can be used to analyze the magnetodielectric response.

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Lanzillotti-Kimura, N. D., A. Fainstein, A. Lemaître et B. Jusserand. « Nanowave devices for terahertz acoustic phonons ». Applied Physics Letters 88, n^o 8 (20 février 2006) : 083113. http://dx.doi.org/10.1063/1.2178415.

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Makler, Sergio S., M. I. Vasilevskiy, E. V. Anda, D. E. Tuyarot, J. Weberszpil et H. M. Pastawski. « A source of terahertz coherent phonons ». Journal of Physics : Condensed Matter 10, n^o 26 (6 juillet 1998) : 5905–21. http://dx.doi.org/10.1088/0953-8984/10/26/017.

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Vasileiadis, Thomas, Juan Sebastian Reparaz et Bartlomiej Graczykowski. « Phonon transport in the gigahertz to terahertz range : Confinement, topology, and second sound ». Journal of Applied Physics 131, n^o 18 (14 mai 2022) : 180901. http://dx.doi.org/10.1063/5.0073508.

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Transport of heat and hypersound with gigahertz (GHz) to terahertz (THz) phonons is crucial for heat management in electronics, mediating signal processing with microwave radiation, thermoelectrics, and various types of sensors based on nanomechanical resonators. Efficient control of heat and sound transport requires new materials, novel experimental techniques, and a detailed knowledge of the interaction of phonons with other elementary excitations. Wave-like heat transport, also known as second sound, has recently attracted renewed attention since it provides several opportunities for overcoming some of the limitations imposed by diffusive transport (Fourier’s regime). The frequency-domain detection of GHz-to-THz phonons can be carried out in a remote, non-destructive, and all-optical manner. The ongoing development of nanodevices and metamaterials made of low-dimensional nanostructures will require spatially resolved, time-resolved, and anisotropic measurements of phonon-related properties. These tasks can be accomplished with Brillouin light scattering (BLS) and various newly developed variants of this method, such as pumped-BLS. In the near future, pumped-BLS is expected to become useful for characterizing GHz topological nanophononics. Finally, second-sound phenomena can be observed with all-optical methods like frequency-domain thermoreflectance.

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Woerner, Michael, Carmine Somma, Klaus Reimann, Thomas Elsaesser, Igal Brener, John L. Reno, Yuanmu Yang et Peter Q. Liu. « Terahertz driven amplification of coherent optical phonons in GaAs coupled to metallic dog-bone resonators ». EPJ Web of Conferences 205 (2019) : 05007. http://dx.doi.org/10.1051/epjconf/201920505007.

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Two-dimensional terahertz spectroscopy on an AlAs/GaAs nanostructure covered by field-enhancing dog-bone resonators shows signatures of coherent optical phonon amplification. Amplification is due to stimulated phonon emission by a terahertz-driven electron current.

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Caldwell, Joshua D., Lucas Lindsay, Vincenzo Giannini, Igor Vurgaftman, Thomas L. Reinecke, Stefan A. Maier et Orest J. Glembocki. « Low-loss, infrared and terahertz nanophotonics using surface phonon polaritons ». Nanophotonics 4, n^o 1 (13 avril 2015) : 44–68. http://dx.doi.org/10.1515/nanoph-2014-0003.

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AbstractThe excitation of surface-phonon-polariton (SPhP) modes in polar dielectric crystals and the associated new developments in the field of SPhPs are reviewed. The emphasis of this work is on providing an understanding of the general phenomenon, including the origin of the Reststrahlen band, the role that optical phonons in polar dielectric lattices play in supporting sub-diffraction-limited modes and how the relatively long optical phonon lifetimes can lead to the low optical losses observed within these materials. Based on this overview, the achievements attained to date and the potential technological advantages of these materials are discussed for localized modes in nanostructures, propagating modes on surfaces and in waveguides and novel metamaterial designs, with the goal of realizing low-loss nanophotonics and metamaterials in the mid-infrared to terahertz spectral ranges.

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Thèses sur le sujet "TeraHertz phonons"

Li, Xian Ph D. Massachusetts Institute of Technology. « Terahertz-field-induced nonlinearity in phonons, electrons and spins ». Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122713.

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Chemistry, 2019
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 189-210).
In this thesis, I describe work aimed at understanding nonlinear material responses initiated by strong terahertz (THz) field excitation. I discuss two aspects of nonlinear THz spectroscopy in condensed-matter materials: developments of experimental THz capabilities and spectroscopy methods and their applications in investigating ultrafast nonlinear dynamics in different classes of materials. I first describe the THz generation, detection and spectroscopy methods, which are the basis of all of our studies. We have generated strong single- and multi-cycle THz pulses covering several spectral ranges using inorganic and organic crystals and developed linear and nonlinear THz spectroscopy techniques to interrogate light-matter interactions based on different observables and/or symmetry criteria.
We have demonstrated a new method for studying time-domain electron paramagnetic resonance that allows us to measure THz-frequency fine structures of spin energy levels on a tabletop and have developed nonlinear two-dimensional (2D) magnetic resonance spectroscopy to distinguish nonlinear THz-spin interaction pathways. We also show that THz-pump, optical-probe spectroscopy, including THz field-induced second-harmonic generation spectroscopy and THz Kerr effect spectroscopy, can be extended to study phase transitions in quantum paraelectric and topological materials. We have employed the THz methods to drive and detect nonlinear responses from several degrees of freedom in the materials. We have demonstrated collective coherent control over material structure by inducing a quantum paraelectric to ferroelectric phase transition using intense THz electric fields in strontium titanate.
We show that a single-cycle THz field is able to drive ions along the microscopic pathway leading directly to their locations in a new crystalline phase on an ultrafast timescale. We have driven highly nonlinear lattice and electronic responses in a topological crystalline insulator by dynamically perturbing the protecting crystalline symmetry through THz phonon excitation. We have observed oscillations in optical reflectivity that may be associated with electronic gap opening and modulation in the topological surface states. Finally, we have demonstrated nonlinear manipulation of collective spin waves in a canted antiferromagnet using strong THz magnetic fields and we have observed full sets of the second- and third-order nonlinear responses in 2D THz magnetic resonance spectra, which are accurately reproduced in our numerical simulations.
by Xian Li.
Ph. D.
Ph.D. Massachusetts Institute of Technology, Department of Chemistry

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Warren, Matthew Timothy. « Time-Domain Terahertz Studies of Strongly Correlated GeV4S8 and Osmate Double-Perovskites ». The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1512066420271281.

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Kasai, S., T. Katagiri, J. Takayanagi, K. Kawase et T. Ouchi. « Reduction of phonon resonant terahertz wave absorption in photoconductive switches using epitaxial layer transfer ». American Institite of Physics, 2009. http://hdl.handle.net/2237/12632.

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Hibberd, Morgan. « Studying low frequency vibrational modes using ultrafast techniques ». Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/studying-low-frequency-vibrational-modes-using-ultrafast-techniques(4f2da8db-befe-4c37-a6ae-42d069c54dd5).html.

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In this thesis, I report on the investigation of the low frequency vibrational modes in a number of different systems using ultrafast spectroscopic techniques. These consist of biological systems, including the enzyme, morphinone reductase (MR) and the related biomolecules, riboflavin (Rb) and flavin mononucleotide (FMN), as well as non-biological systems, including the semiconductor gallium nitride (GaN) and gold nanoparticles (Au NPs). The term low frequency refers to terahertz (THz) frequencies, where vibrational modes exist at the molecular level, with molecular rotations, lattice vibrations and inter- and intra-molecular vibrations occurring in the THz spectral range. These vibrational modes occur on sub-picosecond timescales and therefore ultrafast techniques utilising femtosecond laser pulses provide a means of studying these modes, and are employed throughout this thesis. The two ultrafast techniques of transient absorption (TA) spectroscopy and terahertz time-domain spectroscopy (THz-TDS) were used. Firstly, a high-repetition rate transient absorption (HRRTA) spectrometer was commissioned to perform pump-probe measurements with an ultraviolet pump and broadband visible probe. The performance of the HRRTA spectrometer was benchmarked using Au NPs and used to investigate the existence of a promoting vibration in MR contributing to the catalysis process, predicted to occur at THz frequencies. Weak oscillations were detected in the charge-transfer absorption band of MR bound to the non-reactive cofactor 1,4,5,6-tetra-hydro-nicotinamide adenine dinucleotide (NADH4), with a frequency of approximately 1.5 THz and provide evidence of the first direct observation of a promoting vibration in an enzyme. To complement the TA measurements, THz-TDS was also used to obtain direct measurements of the absorption at THz frequencies. Due to the challenge of studying water-based biological samples, an initial investigation was performed on a wurtzite GaN wafer, which exhibited optical phonon modes in the THz frequency range that were found to determine the dielectric response of the semi-insulating semiconductor wafer. Use of a non-polar m-plane wafer allowed the anisotropic nature to be observed and values of 9.22 ± 0.02 and 10.32 ± 0.03 for the static dielectric constants were obtained for the THz electric field polarised both perpendicular and parallel to the c-axis of the wurtzite GaN wafer, respectively. Finally, biological studies using THz-TDS were performed with measurements on Rb pellets and films revealing vibrational modes in the THz region. The sharp absorption features were not observed in FMN, despite a small difference in molecular content from Rb, and dehydration was required to reveal small amplitude absorption features. Final measurements on MR and MR-NADH4 films were carried out and evidence of absorption features in the THz frequency range were observed, however further work is required to determine the precise origin of these features.

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Freeman, Will. « Terahertz quantum cascade structures using step wells and longitudinal optical-phonon scattering ». Monterey, Calif. : Naval Postgraduate School, 2009. http://edocs.nps.edu/npspubs/scholarly/dissert/2009/Jun/09Jun%5FFreeman%5FPhD.pdf.

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Dissertation (Ph.D. in Physics)--Naval Postgraduate School, June 2009.
Dissertation supervisor: Karunasiri, Gamani. "June 2009." Description based on title screen as viewed on July 14, 2009. Author(s) subject terms: Terahertz, THz, Quantum cascade structure, QC structure, Quantum cascade laser, QCL, Step well, Longitudinal optical-phonon, LO-phonon, Electron-phonon scattering, Electronelectron scattering, Impurity scattering, Interface roughness scattering, Optical transition, Electron transport, Monte Carlo method, Metal-metal waveguide, Surface plasmon waveguide Includes bibliographical references (p. 103-108). Also available in print.

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Mährlein, Sebastian F. [Verfasser]. « Nonlinear Terahertz Phononics : A Novel Route to Controlling Matter / Sebastian F. Mährlein ». Berlin : Freie Universität Berlin, 2017. http://d-nb.info/1135608059/34.

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Knighton, Brittany E. « Nonlinear Ultrafast Excitation and Two-Dimensional Terahertz Spectroscopy of Solids ». BYU ScholarsArchive, 2021. https://scholarsarchive.byu.edu/etd/9190.

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Ultrafast spectroscopy allows us to probe and understand material properties. With it, we can measure phonon-polaritons (optical phonons coupled with light) and the resulting dispersion curve in lithium niobate. Customizing the excitation source in ultrafast measurements can excite phonon modes to large amplitudes, allowing the experimental exploration of the Potential Energy Surface in solids. However, stronger pump fluences and bigger signal isn't always the answer in ultrafast spectroscopy. When sample signals and their nonlinear and mechanisms cannot be distinguished with 1D measurements, simple 2D THz measurements are a great place to start searching for distinct factors as was the case in cadmium tungstate. 2D measurements when paired with modeling and first principles calculations can reveal cutting edge information about exciting materials.

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Nguema, Agnandji Edwin. « Génération et détection Terahertz : application à la caractérisation de matériaux en couches minces ». Thesis, Bordeaux 1, 2009. http://www.theses.fr/2009BOR13796/document.

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Ce travail porte sur la caractérisation de matériaux en couches minces par spectroscopie terahertz dépendant du temps. Dans ce but, nous avons élaboré un banc d’analyse spectroscopique dont l’émission et la détection terahertz reposent sur l’utilisation de laser femtoseconde, de semi-conducteurs, de photocommutateurs ultrarapides ou de cristaux électro-optiques. La réponse diélectrique quantitative de matériaux ferroélectriques (titanate de baryum/ - Ba1-xSrxTiO3) déposés sous forme de couches minces, a permis de mettre en évidence l’importance des modes mous de phonon par une étude en température. Enfin, le comportement électromagnétique de polymères conducteurs à base de polyaniline a été effectué notamment leur efficacité de blindage en bande millimétrique et submillimétrique
This work concerns the characterization of thin film materials by terahertz time domain spectroscopy. For this purpose, we elaborated a terahertz setup in which the terahertz emission and terahertz detection are based on the use of femtosecond laser, semiconductors, ultrafast photoswitches or electro-optic crystals. The study of dielectric function of ferroelectrics thin film (barium titanate/-Ba1-xSrxTiO3) with temperature, give the importance of soft phonon mode. Finally, the electromagnetic behavior of conducting polymers based on polyaniline was made, in particular their shelding effectiveness in millimeter and sub-millimeter length

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Souza, Fabricio Macedo de. « Dinâmica de plasma e fônon e emissão de radiação terahertz em superfícies de GaAs e telúrio excitadas por pulsos ultracurtos ». Universidade de São Paulo, 2000. http://www.teses.usp.br/teses/disponiveis/76/76131/tde-18112013-111000/.

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Após a excitação de uma amostra semicondutora por um pulso ultracurto, os fotoporadores interagem com a rede excitando modos longitudinais ópticos. Essa interação provoca variações no índice de refração do material, produzindo modulações na resposta óptica do meio (efeito eletro-óptico). Por outro lado, esta dinâmica origina polarizações dependentes do tempo o que gera emissão de radiação terahertz. Experimentos recentes (pump-probe) observaram modulações do campo através de medidas da refletividade resolvidas no tempo. A refletividade e o campo estão relacionados segundo o efeito eletro-óptico. Também se resolve temporalmente o campo irradiado pela amostra, através de antenas que operam na faixa de terahertz. Tanto as medidas eletro-ópticas quanto de emissão terahertz fornecem informações sobre a interação dinâmica do plasma com a rede após a excitação óptica. Nesse trabalho simulamos a interação dinâmica de plasma e fônons em n-GaAs e Telúrio (\"bulk\") após estes serem excitados por um pulso ultracurto. Utilizamos equações hidrodinâmicas para descrever transporte de cargas e uma equação fenomenológica de oscilador harmônico forçado, para descrever oscilações longitudinais ópticas da rede. Complementando nossa descrição temos a equação de Poisson, com a qual calculamos o campo gerado pelo plasma e pela polarização da rede semicondutora. Essas equações constituem um sistema de seis equações diferencias (quatro parciais) acopladas. Para resolvê-las utilizamos o método das diferenças finitas. Do cálculo numérico obtemos a evolução temporal do campo elétrico no interior do material. Com esse campo determinamos as freqüências de oscilação do sistema e calculamos o campo irradiado. Nossos resultados apresentam acordo qualitativo com os experimentos
Above-band-gap optical excitation of semiconductors generates highly non-equilibrium photocarriers which interact with phonons thus exciting vibrational modes in the system. This interaction induces refractive-index changes via the electro-optic effect. Moreover it gives rise to electromagnetic radiation at characteristic frequencies (terahertz). Both effects have been measured by time-resolved ultra fast spectroscopy. Recent pump-probe experiments have found strong modulations of the internal electric field through electro-optic measurements. The emitted electromagnetic radiation has also been detected by a terahertz dipole antenna. Both electro-optic and terahertz emission measurements provide information about the coupled dynamics of photocarriers and phonons. In this work we simulate the dynamics of plasmon-phonon coupled modes in n-GaAs and Tellurium (bulk) following ultrafast laser excitation. The time evolution of the photocarrier densities and currents is described semi classically in terms of the moments of the Boltzmann equation. Phonon effects are accounted for by considering a phenomenological driven-harmonic-oscillator equation, which is coupled to the electron-hole plasma via Poisson\'s equation. These equations constitute a coupled set of differential equations. We use finite differencing to solve these equations. From the numerical results for the evolution of internal fields we can calculate both the characteristic frequencies of system and its terahertz radiation spectrum. Our results are consistent with recent experimental data

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Vassant, Simon. « Contrôle optique et électrique de réflectivité THz assistée par phonon-polaritons de surface ». Phd thesis, Ecole Centrale Paris, 2011. http://tel.archives-ouvertes.fr/tel-00601767.

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Le travail de thèse porte sur la conception et la réalisation de deux modulateurs optiques assistés par phonon-polaritons de surface fonctionnant en réflectivité, autour de 8.5 THz, à température ambiante. Nous avons dans un premier temps validé expérimentalement la description théorique du couplage du champ propagatif aux phonons polaritons de surface pour un réseau de GaAs grâce à des mesures de réflectivité THz résolues angulairement. Nous montrons l'importance de la géométrie de la structure pour une description quantitative du couplage. Nous avons réalisé un modulateur de réflectivité THz contrôlé optiquement. La structure est un réseau lamellaire de GaAs dopé , de période inférieure à la longueur d'onde supportant un mode composé de plasmon-phonon-polaritons de surface se propageant le long des murs du réseau. L'éclairement de la structure dans le visible modifie la fréquence de résonance THz de ce mode en créant des photo-porteurs dans les murs du réseau et permet ainsi un contrôle actif de la réflectivité.Enfin nous étudions et réalisons un modulateur de réflectivité THz contrôlé électriquement. Nous proposons une structure permettant d'exciter un mode de phonon-polaritons d'interface dans un puits quantique. Ce mode est très confiné dans le puits et présente une forte sur-intensité de champ. Cet effet original est lié à la permittivité du puits proche de zéro à la fréquence du mode d'interface. La perturbation engendrée par des transitions intersous-bandes dans le puits quantique unique permet, en appliquant une tension de l'ordre du volt, de contrôler l'intensité du couplage du champ propagatif au mode du puits, ce qui donne un contrôle actif de la réflectivité de la structure.

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Chapitres de livres sur le sujet "TeraHertz phonons"

Schwartz, H., K. F. Renk, A. Berke, A. P. Mayer et R. K. Wehner. « Terahertz-Phonons in Diamond ». Dans Phonon Scattering in Condensed Matter V, 362–64. Berlin, Heidelberg : Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-82912-3_103.

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Happek, U., W. W. Fischer et J. A. Campbell. « Terahertz Phonons in Highly Disordered Crystals ». Dans Springer Series in Solid-State Sciences, 306–10. Berlin, Heidelberg : Springer Berlin Heidelberg, 1993. http://dx.doi.org/10.1007/978-3-642-84888-9_122.

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Ulbrich, R. G. « Generation, Propagation and Detection of Terahertz Phonons In Gallium Arsenide ». Dans Nonequilibrium Phonon Dynamics, 101–27. Boston, MA : Springer US, 1985. http://dx.doi.org/10.1007/978-1-4613-2501-7_3.

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Carpinteri, Alberto. « TeraHertz Phonons and Piezonuclear Reactions from Nano-scale Mechanical Instabilities ». Dans Acoustic, Electromagnetic, Neutron Emissions from Fracture and Earthquakes, 1–10. Cham : Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-16955-2_1.

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Akimov, A. V., A. A. Kaplyanskii et E. S. Moskalenko. « Nonequilibrium Terahertz Range Acoustic Phonons and Luminescence of Excitons in Semiconductors ». Dans Laser Optics of Condensed Matter, 37–46. Boston, MA : Springer US, 1991. http://dx.doi.org/10.1007/978-1-4615-3726-7_6.

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Mizoguchi, K., M. Nakayama, S. Saito, A. Syouji et K. Sakai. « Dynamical Properties of Terahertz Radiation from Coherent Longitudinal Optical Phonons Confined in a GaAs/AlAs Multiple Quantum Well ». Dans Ultrafast Phenomena XV, 790–92. Berlin, Heidelberg : Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-68781-8_252.

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Mizoguchi, K., Y. Kanzawa, M. Nakayama, S. Saito et K. Sakai. « Terahertz wave from coherent LO phonon in a GaAs/AlAs multiple quantum well under an electric field ». Dans Springer Series in Chemical Physics, 681–83. Berlin, Heidelberg : Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-95946-5_221.

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Basak, Tista, et Tushima Basak. « Recent Advances in Graphene Based Plasmonics ». Dans Photonic Materials : Recent Advances and Emerging Applications, 56–84. BENTHAM SCIENCE PUBLISHERS, 2023. http://dx.doi.org/10.2174/9789815049756123010007.

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Plasmonics is an emerging and fast-growing branch of science and technology that focuses on the coupling of light to the free electron density in metals, resulting in strong electromagnetic field enhancement due to confinement of light into sub-wavelength dimensions beyond the diffraction limit. The development of novel photonic and optoelectronic devices based on metal-based plasmonics is however plagued by the high loss at optical frequencies, originating partly from inter-band electronic transitions and lack of electrical tunability, practically limiting their potential applications in the terahertz (THz) and mid-IR spectrum range. The recent successful exfoliation of graphene from graphite has rendered a breakthrough in the realm of plasmonics due to its phenomenal properties such as exceptionally tight light confinement, extremely long plasmon lifetime, high carrier mobility leading to a relatively low level of losses, strong optical nonlinearity and electrostatically as well as chemically tunable response. These versatile features of graphene can effectively address the challenges faced by metals, and hence the physics and potential applications of graphene-based plasmonics have triggered increasing attention of industry, academic and research fraternity in recent years. This chapter provides a comprehensive description of the theoretical approaches adopted to investigate the dispersion relation of graphene surface plasmons, types of graphene surface plasmons and their interactions with photons, phonons and electrons, experimental techniques to detect surface plasmons, the behaviour of surface plasmons in graphene nanostructures and the recent applications of graphene-based plasmonics.

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Sharma, Prince, Veerpal Singh Awana et Mahesh Kumar. « Temperature-Dependent Evaluation of Charge Carriers and Terahertz Generation in Bismuth and Antimony-Based Chalcogenides ». Dans Chalcogens [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.102887.

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Bismuth and antimony-based chalcogenides have been extensively publicized in recent years owing to their intrinsic characteristics and inherent topological character. Such a system contains Bi2Se3, Bi2Te3, Sb2Te3, etc. The single crystalline facets of these samples were discovered to have a generation of ~2 THz while having a giant magneto-resistance of around ~300%. These inherent and dynamical features of the system make it resilient for several applications in optoelectronics and spintronics. The temperature-dependent assessment of conductivity, terahertz generation, and charge carrier dynamics aids in understanding the fundamental phenomena in the carrier mechanism of the chalcogenides. This chapter contains the essential fundamental knowledge of the single crystal chalcogenides via charge carrier & phonon dynamics and their response in the terahertz frequency domain.

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Yamaguchi, Masashi, Minfeng Wang et Pablo Suarez. « TERAHERTZ PHONON-POLARITON IMAGING FOR THE APPLICATION OF CHEMICAL DETECTION ». Dans Selected Topics in Electronics and Systems, 163–73. WORLD SCIENTIFIC, 2007. http://dx.doi.org/10.1142/9789812771803_0013.

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Actes de conférences sur le sujet "TeraHertz phonons"

Liu, H. C., C. Y. Song, Z. R. Wasilewski, J. A. Gupta et M. Buchanan. « Designing phonons for active use in terahertz devices ». Dans SPIE OPTO : Integrated Optoelectronic Devices, sous la direction de Manijeh Razeghi, Rengarajan Sudharsanan et Gail J. Brown. SPIE, 2009. http://dx.doi.org/10.1117/12.807532.

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Tani, Masahiko, Ryoichi Fukasawa, Michael Herrmann, Kiyomi Sakai, Shin-ichi Nakashima, Nobuya Yoshioka, Akihiro Ishida et Hiroshi Fujiyasu. « Terahertz emission spectroscopy of coherent phonons in semiconductors ». Dans Optoelectronics '99 - Integrated Optoelectronic Devices, sous la direction de Kong-Thon F. Tsen. SPIE, 1999. http://dx.doi.org/10.1117/12.349285.

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Weiner, A. M., D. E. Leaird, G. P. Wiederrecht et K. A. Nelson. « Resonant Excitation of Coherent Optic Phonons by Femtosecond Multiple-Pulse Impulsive Stimulated Raman Scattering ». Dans International Conference on Ultrafast Phenomena. Washington, D.C. : Optica Publishing Group, 1990. http://dx.doi.org/10.1364/up.1990.thd2.

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Generation of coherent optic phonons through impulsive stimulated Raman scattering (ISRS) can occur whenever a sufficiently short optical pulse passes through a Raman-active medium [1-3]. In this paper we report the application of specially shaped femtosecond pulse trains to achieve improved control over coherent vibrational motion. In particular, we demonstrate "multiple-pulse" ISRS, in which terahertz-rate trains of fsec pulses are used for repetitive impulsive excitation of optic phonons. By matching the pulse repetition rate to a particular phonon frequency, we are able to select and amplify individual vibrational modes [4]. Each successive pulse in the sequence arrives at the sample in phase to amplify the selected mode, analogous to repetitively pushing a child on a swing.

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Weng, Qianchun, Robb Puttock, Craig Barton, Vishal Panchal, Le Yang, Zhenghua An, Yusuke Kajihara, Wei Lu, Alexander Tzalenchuk et Susumu Komiyama. « Nanothermometry of electrons and phonons ». Dans 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz 2018). IEEE, 2018. http://dx.doi.org/10.1109/irmmw-thz.2018.8509939.

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Takeuchi, Hideo, Shuichi Tsuruta et Masaaki Nakayama. « Dynamical characteristics of a coherent longitudinal optical phonon in a GaAs buffer layer optically covered with a GaSb top epitaxial layer investigated with use of terahertz spectroscopy ». Dans PHONONS 2012 : XIV International Conference on Phonon Scattering in Condensed Matter. AIP, 2012. http://dx.doi.org/10.1063/1.4772529.

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Zheng, Jiaoyang, Guru Khalsa, Nicole A. Benedek et Jeffrey Moses. « Two-pulse enabled coherent control of structural dynamics ». Dans International Conference on Ultrafast Phenomena. Washington, D.C. : Optica Publishing Group, 2022. http://dx.doi.org/10.1364/up.2022.w4a.20.

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We predict a new pathway for ultrafast coherent control of fully symmetric Raman phonons, allowing manipulation of sign, magnitude, and temporal response, enabled by the nonlinear lattice polarizability and a two-terahertz-pulse excitation sequence.

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Feofilov, S. P., et Alexander A. Kaplyanskii. « Nonequilibrium terahertz phonons in spatially confined aluminum oxide crystalline materials studied by the Cr3+fluorescent phonon detector ». Dans Tenth Feofilov Symposium on Spectroscopy of Crystals Activated by Rare Earth and Transitional Ions, sous la direction de Alexander I. Ryskin et V. F. Masterov. SPIE, 1996. http://dx.doi.org/10.1117/12.229136.

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Gundareva, I., V. Pavlovskiy et Y. Divin. « THz Josephson spectroscopy of optical phonons in YBa2Cu3O7−x ». Dans 2017 42nd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz). IEEE, 2017. http://dx.doi.org/10.1109/irmmw-thz.2017.8066926.

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Fu, Zhengping, et Masashi Yamaguchi. « Excitation of coherent phonons in GaAs by broadband THz pulses ». Dans 2014 39th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz). IEEE, 2014. http://dx.doi.org/10.1109/irmmw-thz.2014.6956037.

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Völkel, Alexandra, et Georg Herink. « Ultrafast Raman-induced Coupling of Femtosecond Soliton Molecules via Optical Terahertz Phonons ». Dans CLEO : QELS_Fundamental Science. Washington, D.C. : OSA, 2021. http://dx.doi.org/10.1364/cleo_qels.2021.fw4k.3.

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Rapports d'organisations sur le sujet "TeraHertz phonons"

Gelmont, Boris. Simulation of Terahertz Frequency Sources. Polar-Optical Phonon Enhancement of Harmonic Generation in Schottky Diodes. Fort Belvoir, VA : Defense Technical Information Center, septembre 2002. http://dx.doi.org/10.21236/ada413032.

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