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The sculpting of ultracold neutral plasmas represents a frontier in the experimental study of collective modes in strongly coupled plasmas. By extending the range of accessible length scales to less than tens of microns we gain access to a regime where The sculpting of ultracold neutral plasmas represents a frontier in the experimental study of collective modes in strongly coupled plasmas. By extending the range of accessible length scales to less than tens of microns we gain access to a regime where strong coupling's effects are predicted yet largely untested. To this effort, high resolution optical systems were designed, bench tested and implemented for sculpting and imaging ultracold neutral plasmas. Many complications and unexpected effects were documented to assist future experimental design considerations, including, those due to saturation and optical thickness, both of which limit the utility of 461 nm push beam modulations. It was concluded that sculpting should be performed on the 412 nm ionizing beam and real-time density space analysis is reliable for spatial frequencies up to 5 cyc/mm by using 4X magnified imaging. Higher spatial frequencies benefit from velocity space analysis due to extremely fast dynamics and low intensity levels.

Depuis 2012, les pérovskites hybrides halogénées de type CH3NH3PbX3 (X = I, Br ou Cl) sont apparues comme très prometteuses non seulement dans le domaine du photovoltaïque mais aussi pour les dispositifs émetteurs de lumière comme les diodes électroluminescentes et les lasers. L'un des avantages cruciaux de ces matériaux semiconducteurs est leur méthode de déposition à basse température et en solution. Le réglage de la longueur d'onde d'émission des pérovskites dans tout le spectre visible par de simples substitutions chimiques dans la partie halogénée est un autre atout. En particulier, les pérovskites halogénées montrent une grande efficacité de luminescence dans le vert et pourraient répondre au problème du "green gap" dans les sources laser (le "green gap" fait référence à la baisse d'efficacité des diodes électroluminescente et diodes laser à semi-conducteurs émettant dans le vert).Le travail de doctorat mené ici a porté sur la réalisation d’un laser pompé optiquement à base de la pérovskite hybride CH3NH3PbBr3 émettant dans le vert. La structure réalisée consiste en une microcavité verticale à base d’une couche mince de 100 nanomètres de CH3NH3PbBr3 déposé par "spin-coating" (dépôt par enduction centrifuge), insérée entre un miroir diélectrique et un miroir métallique. Nous avons démontré, à température ambiante, le régime de couplage fort entre le mode photonique de la microcavité et l'exciton de la pérovskite. Ce régime de couplage fort conduit à la création de quasi-particules appelées les exciton-polaritons, qui sont une superposition cohérente d’états photonique et excitonique. En augmentant la puissance injectée optiquement, nous avons obtenu un effet laser dans cette microcavité. L’étude des propriétés d’émission de ce laser met en évidence que nous avons réalisé un laser aléatoire, émettant dans le vert, filtré directionnellement par la courbe de dispersion du polariton de basse énergie. Ce filtrage par la courbe de dispersion du polariton permet le contrôle de la directionnalité de l’émission laser sur une grande gamme d’angles : des angles aussi grands que 22° ont été obtenus expérimentalement. / Since 2012, the hybrid halide perovskites of CH3NH3PbX3 (X = I, Br or Cl) type have emerged as very promising not only in the field of photovoltaics but also for light-emitting devices such as light-emitting diodes and lasers. One of the crucial advantages of these semiconductor materials is their low temperature and solution deposition method. The tuning of the perovskites emission wavelength throughout the visible spectrum by simple chemistry substitutions in the halogenated part is another asset. In particular, the halide perovskites show a high luminescence efficiency in the green and could address the "green gap" problem in laser sources (the "green gap" refers to the drop in efficiency of light-emitting diodes and laser diodes emitting in the green).The thesis work carried out here is focused on the development of an optically pumped laser based on the hybrid halide perovskite CH3NH3PbBr3 emitting in the green. The structure consists of a vertical microcavity based on a 100-nanometre thin film of CH3NH3PbBr3 deposited by spin-coating, inserted between a dielectric mirror and a metal mirror. We have demonstrated, at room temperature, the strong coupling regime between the microcavity photonic mode and the exciton of the perovskite. This strong coupling regime leads to the creation of quasi-particles called exciton-polaritons, which are a coherent superposition of photonic and excitonic states. By increasing the optically injected power, we obtained a laser effect in this microcavity. The study of the emission properties of this laser shows that we have produced a random laser, emitting in the green, filtered directionally by the dispersion curve of the lower polariton. This filtering by the polariton dispersion curve allows the directionality of the laser emission to be controlled over a wide range of angles: angles as large as 22° were obtained experimentally.

Les pérovskites hybrides organiques-inorganiques ont attiré l'attention en raison de leurs applications potentielles dans des dispositifs optiques et plus récemment dans les dispositifs photovoltaïques. L'arrangement cristallin des pérovskites forme une structure en multi-puits quantiques dans laquelle les états excitoniques présentent une grande force d'oscillateur et une énergie de liaison importante, ce qui rend la réalisation de microcavités dans le régime de couplage fort possible à la température ambiante. Etant un matériau relativement nouveau, les pérovskites ont encore beaucoup de comportements qui ne sont pas bien compris et beaucoup de travail de recherche est nécessaire. Ce manuscrit est divisé en deux parties. Dans la première partie, la dynamique des excitons sur une pérovskite particulière (C6H5-C2H4-NH3)2PbI4 (PEPI) est étudiée à température ambiante par mesure de type pompe-sonde sous faible et fort régime d'excitation. Sous forte densité d'excitation, un processus de recombinaison Auger des excitons est présent. Une relaxation intrabande ultra-rapide a été observée. La deuxième partie du manuscrit est consacrée à l'étude de la microphotoluminescence à temperature ambiante de microcavités à base de PEPI à haut facteur de qualité. Des nouvelles pérovskites avec des propriétés optimisées (propriétés optiques d'émission, rugosité de surface et photostabilité) ont également été synthétisées. / The reason for choosing this thesis comes from the fact that in the near future,I would like to gain more knowledge and experience in scientific research and especially in the study of non linear effects in optical microcavities where new opportunities are opened and high efficient light sources could be exploited.In last ten years, an increasing number of studies are dedicated on hybrid organic-inorganic materials, due to the possibility of combining the properties both of inorganic(high mobility, electrical pumping, band engineering ) and of organic materials (low cost technology, high luminescence quantum yield at room temperature).In this context , organic-inorganic perovskites having a chemical formula (R-NH3)2MX4 where M is a metal, X halogen and R an organic chains presents a natural hybrid system . When deposited by spin coating, the molecules self-organize to form a multiple quantum wells structure. Because of the strong binding energy, optical features can be seen at room temperature. Moreover, such pervoskite presents great flexibility in their optical properties such that the spectral position of the excitonic transitions can be tailored by substituting different halides X, and the photoluminescence efficiency can be tailored by changing the organic part R. This kind of perovskites has been studied both for fundamental studies and for applications in optoelectronics. In order to increase the coupling between light and matter (exciton), perovskite has been inserted in planar microcavity and strong coupling regime has been achieved at room temperature. The strong coupling of light with exciton give rise to polariton quasi-particles, which have new properties not seen in either photons or excitons. In order to go further and have better study in stimulated scattering of polaritons in these microcavities ,a better understanding of the electronic structure as well as the excitonic interactions in these quantum wells are necessary due to the lack of information on the dynamic and on the carrier interaction of these structures. In order to study the hybrid polaritons, it will be first necessary to improve the knowledge about the relaxation in the perovskite layers. So, ultrafast pump-probe experiments will be performed on hybrid microcavities, and also on perovskite layers.

In this thesis, a leading-order QCD analysis of structure functions in neutrinonucleon interactions is performed. From the CCFR nucleon structure function data, the QCD parameter Lambda has been extracted. This measurement also corresponds to a measurement of the strong coupling constant. Two fits to the data have been performed, the nonsinglet-only fit and the singlet-nonsinglet combined fit. The result for Lambda was found to be 289 +62 &iexcl / 59 &sect / 76 MeV, where the errors are statistical and systematical, respectively. This result is compared to the world-wide measurements of this quantity. In order to verify the agreement, also the logarithmic slopes of the QCD model and the structure function data are calculated and compared.

xv, 204 p. : ill. (some col.) A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / This thesis reports on progress made toward realizing strong cavity quantum electrodynamics coupling in a novel micro-cavity operating close to the hemispherical limit. Micro-cavities are ubiquitous wherever the aim is observing strong interactions in the low-energy limit. The cavity used in this work boasts a novel combination of properties. It utilizes a curved mirror with radius in the range of 40-60 µm that exhibits high reflectivity over a large solid angle and is capable of producing a diffraction limited mode waist in the approach to the hemispherical limit. This small waist implies a correspondingly small effective mode volume due to concentration of the field into a small transverse distance. The cavity assembled for this investigation possesses suitably low loss (suitably low linewidth) to observe vacuum Rabi splitting under suitable conditions. According to best estimates for the relevant system parameters, this system should be capable of displaying strong coupling. The dipole coupling strength, cavity loss and quantum dot dephasing rates are estimated to be, respectively, g = 35µeV, κ = 30µeV, and γ = 15µeV. A survey of two different distributed Bragg reflector (DBR) samples was carried out. Four different probe lasers were used to measure transmission spectra for the coupled cavity-QED system. The system initially failed to display strong coupling due to the available lasers being too far from the design wavelength of the spacer layer, corresponding to a loss of field strength at the location of the quantum dots. Unfortunately, the only available lasers capable of probing the design wavelength of the spacer layer had technical problems that prevented us from obtaining clean spectra. Both a Ti:Al 2 O 3 and a diode laser were used to measure transmission over the design wavelength range. The cavity used here has many promising features and should be capable of displaying strong coupling. It is believed that with a laser system centered at the design wavelength and possessing low enough linewidth and single-mode operation across a wide wavelength range strong coupling should be observable in this system. / Committee in charge: Hailin Wang, Chairperson, Physics; Michael Raymer, Advisor, Physics; Jens Noeckel, Member, Physics; Richard Taylor, Member, Physics; Andrew Marcus, Outside Member, Chemistry

Atteindre le régime de couplage fort entre des nanocavités et des systèmes atomiques est un élément clé dans l'information quantique. Durant ma thèse, j'ai designé et fabriqué des nanocavités à cristal photonique en GaInP pour le couplage fort autour de 800 nm, longueur d'onde typique des atomes du Rubidium (780 nm) et de Césium (852 nm), les plus utilisés dans le domaine, ainsi que de l'Argon (811 nm). L'objectif est de faire interagir ces atomes avec la partie évanescente du mode fondamental de la nanocavité. Pour cela, un facteur de qualité de l'ordre de 8.10^4 et un volume modal inférieur à 0,04 µm^3 est nécessaire.La nanocavité est l'élément clé d'une plateforme nanophotonique. Nos plateformes sont composées d'une nanocavité à cristal photonique résonant autour de 800 nm, d'un réseau-coupleur pour collecter la lumière issue d'une fibre optique et vice versa et de guides d'alimentation pour transporter la lumière du réseau-coupleur à la nanocavité. Plusieurs défis technologiques ont émergé. La nanocavité doit avoir un fort facteur de qualité et un faible volume modal, le réseau-coupleur doit collecter le maximum de lumière issue de la fibre, les guides d'alimentation doivent transporter la lumière sans perte et, enfin, un mécanisme pour coupler la lumière des guides d'alimentation dans la nanocavité devait être trouvé.J'ai simulé, designé, fabriqué et caractérisé les éléments de ma structure. J'ai obtenu des facteurs de qualité supérieurs à 10^7 en théorie, et de l'ordre de 2.10^4 expérimentalement, détenant ainsi le record pour les cavités en GaInP autour de la longueur d'onde de 800 nm pavant la voie à la réalisation des expériences de couplage fort. / Reaching the strong coupling between nanocavities and atomic systems is a key element for Quantum Information. During my PhD, I designed and fabricated photonic crystal nanocavities in Gallium Indium Phosphide (GaInP)for strong coupling around 800,nm, typical wavelength of atoms such as Rubidium (780,nm), Cesium (852 nm), the most used in this domain, and the Argon atoms (811 nm).The aim of my PhD thesis is to provide with a nanophotonic platform dedicated to strong coupling interaction. For this, nanocavities having optical resonances arounf 800 nm, with quality factors larger than 8.10^4 and mode volumes smaller than 0.04µm^3 are necessary.The nanocavity is a key element of nanophotonic plateform. Our platforms are composed of a photonic crystal nanocavityitself, a grating-coupler in order to collect light from a optic fiber and vice versa and feeding waveguides in order to transport the light from the grating-coupler to the cavity. An efficient nanophtonic platfom for a reaslitic implementation should have a nanocavity with a large Q-factor and small mode volume. The grating-coupler must efficiently collect the light from the optical fiber, and the feeding waveguides must transport the light without losses.I simulated, designed,fabricated and caracterized the elements of my structure. I obtained quality factors larger than 10^7 in theory, and about 2.10^4 experimentally, getting the record for the nanocavities in GaInP around the wavelength 800 nm, which make them close to realize experiments of strong coupling.

Effective field theories can be used to describe measurements at e⁺e⁻ colliders over a wide kinematic range while allowing reliable error predictions and systematic extensions. We show this in two physical situations. First, we give a factorization formula for the e⁺e⁻ thrust distribution dσ/dτ with thrust T and τ = 1 − T based on soft collinear effective theory. The result is applicable for all τ, i.e. in the peak, tail, and far-tail regions. We present a global analysis of all available thrust distribution data measured at center-of-mass energies Q = 35 to 207 GeV in the tail region, where a two parameter fit to the strong coupling constant α(s)(m(Z)) and the leading power correction parameter Ω₁ suffices. We find α(s)(m(Z)) = 0.1135 ± (0.0002)expt ± (0.0005)hadr ± (0.0009)pert, with x²/dof = 0.91, where the displayed 1-sigma errors are the total experimental error, the hadronization uncertainty, and the perturbative theory uncertainty, respectively. In addition, we consider cumulants of the thrust distribution using predictions of the full spectrum for thrust. From a global fit to the first thrust moment we extract α(s)(m(Z)) and Ω₁. We obtain α(s)(m(Z)) = 0.1140 ± (0.0004)exp ± (0.0013)hadr ± (0.0007)pert which is compatible with the value from our tail region fit. The n-th thrust cumulants for n ≥ 2 are completely insensitive to Ω₁, and therefore a good instrument for extracting information on higher order power corrections, Ω'(n)/Qⁿ, from moment data. We find (˜Ω₂)^1/2 = 0.74 ± (0.11)exp ± (0.09)pert GeV. Second, we study the differential cross section dσ/dx of e⁺e⁻-collisions producing a heavy hadron with energy fraction x of the beam energy in the center-of-mass frame. Using a sequence of effective field theories we give a definition of the heavy quark fragmentation function in the endpoint region x → 1. From the perspective of our effective field theory approach we revisit the heavy quark fragmentation function away from the endpoint and outline how to develop a description of the heavy quark fragmentation function valid for all x. Our analysis is focused on Z-boson decays producing one B-meson. Finally, we will give a short outlook of how we want to apply our approach to determine the leading nonperturbative power corrections of the b-quark fragmentation function from LEP experiments.

Ce travail porte sur la mise en œuvre de simulations sur des pales de machines tournantes. Une première partie de la thèse porte sur l’amélioration des performances du couplage fluide-structure. Des nouveaux algorithmes sont présentés. Une nouvelle méthode de déformation de maillage est évaluée. Les développements sont validés à partir de plusieurs cas tests. La deuxième partie porte sur l’application des avancées à des machines tournantes. Une première validation est faite sur une hydrolienne. La vibration d’une pale au passage du mat est étudiée. Enfin, des résultats sur une hydrolienne industrielle sont exposés. / A methodology to simulate blades of turbines is developed. A first part is dedicated to improving the performance of the fluid-structure coupling. New algorithms are presented. A new mesh morphing solution is shown. Developments are validated on many test cases. A second part is dedicated to applying the developments on turbines. A first validation is made on a water turbine. The vibration of a blade interacting with a mast is studied. Finally, some results of an industrial water turbine are shown.

Este trabalho introduz uma nova discretização da banda de condução no método de Grupo de Renormalização Numérico. Com essa técnica, a susceptibilidade magnética do modelo de Anderson de duas impurezas, no limite Kondo, e calculada. Como ilustração, a densidade espectral do modelo também é calculada. A nova técnica baseia-se na simetria de paridade do modelo para discretizar diferentemente à banda de condução associada a cada paridade. Sua extensão ao modelo de rede é indicada. A técnica reduz o tempo computacional e permite usar maiores valores do parâmetro de discretização do que no método tradicional. Para um mesmo tempo de cálculo, nossos resultados são muito mais precisos do que os encontrados na literatura. A susceptibilidade é calculada na aproximação de acoplamento independente da energia. Uma interação de troca, tipo RKKY, é somado ao Hamiltoniano do modelo. Para acoplamento ferromagnético, obtém-se efeito Kondo de dois estágios. O estado fundamental é singleto com defasagem de PI/2 na banda de condução. Para acoplamento antiferromagnético fraco, um efeito Kondo é obtido. Para fortes acoplamentos antiferromagnéticos, o estado fundamental e singleto sem defasagens. Um ponto fixo instável é observado separando as regiões de estado fundamental Kondo e antiferromagnético. Nesse ponto a susceptibilidade é nula e a defasagem é indefinida. / This work introduces an extension of the Numerical Renormalization Group approach to compute thermodynamically properties of impurities in metals, based on a novel logarithmic discretization of the conduction band. On the basis of the new method, the thermal dependence of the magnetic susceptibility for the Kondo limit of the two-impurity Anderson model is computed. As another illustration, the impurity spectral density for the same model is calculated analytically in the weakly correlated regime. The new approach takes advantage of the parity-inversion symmetry of the model to discretize differently the odd and the even conduction channels (for Ni impurities, the conduction band could likewise be divided into Ni channels, each of which would be discretized in a different way). The resulting mesh describes better the continuum of the conduction states than the mesh in the standard Numerical Renormalization Group method; as a consequence, the new procedure is substantially less expensive when computing any given thermodynamical property with a given accuracy, thus we are able to compute the temperature dependence of the magnetic susceptibility with a small fraction of the effort involved in the recently reported computation of the ground state properties for the two impurity Kondo model. As in previous Renormalization Group work, the model Hamiltonian is diagonalized within the energy-independent coupling approximation. One well-known shortcoming of this approximation is its inability to generate antiferromagnetic RKKY couplings between the impurities; to compensate, again following previous work; we have added to the Hamiltonian an artificial exchange coupling Io. For weak antiferromagnetic or ferromagnetic couplings, the effective magnetic moment of the impurities decreases with temperature, and as in the one-impurity Kondo effect, the ground-state conduction band is phase shifted by PI /2. For strong ferromagnetic coupling, the Kondo effect takes place in two stages, one for each conduction channel. For strong antiferromagnetic coupling, the magnetic moment also decreases, rapidly, with temperature, but the ground state conduction-band phase shift is zero. The regions of zero and PI /2 ground-state phase shifts are separated by an unstable fixed point. At this point, the magnetic susceptibility vanishes.