Дисертації з теми "Casimir Effects"
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Noto, Antonio. "Non-equilibrium Casimir interactions : from dynamical to thermal effects." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT279/document.
Повний текст джерелаIn this thesis, after an introduction where we briefly present the general context of Casimir physics, we present the results obtained during the PhD. At first, we show our work about the van der Waals/Casimir-Polder interactions between two atoms in an out-of-equilibrium condition due to their uniformly accelerated motion. We study the system of two uniformly accelerated atoms in vacuum space, when they are in their ground-state and when they are in a correlated state (one excited and one ground-state atom). We analyze this system both with an heuristic semiclassical model and with a more rigorous method, based on a separation of radiation reaction and vacuum fluctuations contributions, that we extend starting from a general procedure known in literature. We find a change of the distance-dependence of the interaction due to the acceleration. We show that Casimir-Polder forces between two relativistic uniformly accelerated atoms, interacting with the scalar field, exhibit a transition from the short-distance thermal-like behavior predicted by the Unruh effect to a long-distance nonthermal behavior, associated with the breakdown of a local inertial description of the system. In addition, we obtain new features of the resonance interaction in the case of atoms interacting with the quantum electromagnetic field.Next, we present our work about a new optomechanical coupling of an effectively oscillating mirror with a Rydberg atoms gas, mediated by the dynamical atom-mirror Casimir-Polder force. We find that this coupling may produce a near-field resonant atomic excitation not related to the excitation of atoms by the few real photons expected by dynamical Casimir effect. In accessible experimental conditions, this excitation probability is significant (about 20%) making the observation of this new dynamical Casimir-Polder effect possible. For this reason, we propose a realistic experimental configuration to realize this system made of a cold atom gas trapped in front of a semiconductor substrate, whose dielectric properties are periodically modulated in time.Finally, we focus on our results obtained for the Casimir-Lifshitz pressure between two different dielectric lamellar gratings. This system is assumed to be in an out-of-thermal-equilibrium configuration, i.e. the two gratings have two different temperatures and they are immersed in a thermal bath having a third temperature. The computation of the pressure is based on a method exploiting the scattering operators of the bodies, deduced using the Fourier modal method. In our numerical results we characterize in detail the behavior of the pressure, both by varying the three temperatures and by changing the geometrical parameters of the gratings. In this way we show that it is possible to tune the force from attractive to repulsive or to strongly reduce the pressure for large ranges of temperatures. Moreover, we stress that the interplay between nonequilibrium effects and geometrical periodicity make this system particularly interesting for the observation of the repulsive Casimir force
De, Aquino Carvalho Joao Carlos. "Interaction Casimir-Polder entre atome de césium et surface de saphir thermiquement émissive." Thesis, Sorbonne Paris Cité, 2018. http://www.theses.fr/2018USPCD054.
Повний текст джерелаIn this thesis we describe measurements of selective reflection spectroscopy that highlight the thermal effects of the Casimir-Polder interaction between atom and surface. In the near field regime, this interaction is governed by a potential decreasing with the cube of the distance between the atom and the surface (van der Waals -vdW- regime of dipoledipole type) We are particularly interested in the excited levels of cesium, we are particularly interested in the excited levels of cesium Cs (7P₁/₂) and Cs (7P₃/₂), which have a dipole coupling to respectively Cs (6D) at 12,15 µm and ~15 µm interacting with a thermally emissive sapphire surface. Sapphire emitting modes are around 12,2 µm, and, thus, these Cs levels are sensitive to a resonant, or non-resonant, vdW interaction. We compare experimentally these levels. The most important result of this thesis is the experimental observation of the difference in behavior of the vdW potential as a function of the window temperature (150 - 800 °C), for the Cs (7P₁/₂) and Cs (7P₃/₂) levels. For the Cs (7P₁/₂) level the vdW potential increases as a function of temperature, while for the Cs (7P₃/₂) level a slight decrease is observed. Selective reflection spectroscopy experiments, probing the Cs (6P₁/₂) level interacting with a hot sapphire surface, were also carried out, which confirm for this level the absence of a temperature effect. The theoretical predictions are refined by the evaluation of the dielectric constant of sapphire as a function of temperature, from new emissivity data provided by the CEMHTI's group, in Orléans. Finally, we use backscattered fluorescence as a diagnosis for the Cs hot cell when exciting Cs (6P ₁/₂) and Cs (7P ₁/₂) levels. We have interpreted, in a manner more consistent than previous literature, sub-Doppler structures observed in the excitation of the fluorescence near the window
Messina, Riccardo. "Casimir-Polder force between atom and surface : geometrical and dynamical effects." Paris 6, 2010. http://www.theses.fr/2010PA066076.
Повний текст джерелаGersberg, Paul. "Confinement and driving effects on continuous and discrete model interfaces." Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0084.
Повний текст джерелаThis thesis examines the properties of the interface between two phases in phase separated systems. We are interested in how finite size effects modify the statistical properties of these interfaces, in particular how the dependence of the free energy on the system size gives rise to long range critical Casimir forces close to thecritical point. Often the interfaces in phase separated systems are described by simplified or coarsegrained models whose only degrees of freedom are the interface height. We review how the statics and dynamics of these interface models can be derived from microscopic spin models and statistical field theories. We then examine finite size effects for continuous interface models such as the Edwards Wilkinson model and discrete models such as the Solid-On-Solid model and discuss their relevance to the critical Casimir effect. In the second part of the thesis we examine models of driven interfaces which have nonequilibrium steady states. We develop a model C type model of an interface which shows a nonequlibrium steady state even with constant driving. The resulting nonequlibrium steady state shows properties seen in experiments on sheared colloidal systems, notably the suppression of height fluctuations but an increase in the fluctuations’correlation length. Finally we propose a new model for one dimensional interfaces which is a modification of the solid on-solid model and containing an extra entropic term ,whose correspondance with physical systems is yet to be found
Priyadarshini, Thiyam. "A study of finite-size and non-perturbative effects on the van der Waals and the Casimir-Polder forces." Licentiate thesis, KTH, Skolan för industriell teknik och management (ITM), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-186225.
Повний текст джерелаQC 20160509
Pujolàs, Boix Oriol. "Quantum effects in brane world scenarios: moduli stabilization and the hierarchy problem." Doctoral thesis, Universitat Autònoma de Barcelona, 2003. http://hdl.handle.net/10803/3354.
Повний текст джерелаque, en estos modelos, la separación entre la escala electrodébil y la de Planck
depende del tamaño de las dimensiones extra. Éste viene caracterizado por un
modo escalar de la métrica conocido como el radión, de forma que una solución
completa al problema de la jerarquía requiere algun mecanismo de estabilización
que fije su valor y explique por qué no se observan las interacciones escalares
transmitidas por el radión.
En esta tesis se estudia la posibilidad de que la energía de Casimir estabilice
el radión (proporcionandole una masa suficientement grande) y generen la
jerarquía de forma natural. Se argumenta que en modelos donde la geometría no
es factorizable, los efectos cuánticos proporcionan un mecanismo de
estabilización capaz de generar y estabilizar la jerarquía. En conctreto, se
discuten los efectos cuánticos en tres familias de modelos.
El primer ejemplo consiste en un modelo tensor--escalar en cinco dimensiones en
que el factor de 'warp' crece como una potencia de la distancia. La presencia de
una simetría de 'scaling' anómala permite estabilizar las posiciones de las branas
y generar la jerarquía de forma natural incluso para potencias pequeñas. No
obstante, las masas de los módulos es suficientemente grande cuando la potencia
del factor de warp es de orden 10 o mayor.
La segunda clase de modelos consiste en un espacio de más de 5 dimensiones donde el
espacio interno y las direcciones no compactas tienen un factor de warp
exponencial. En este modelo, la jerarquía se genera mediante una combinación de
los efectos de redshift y de volumen grande. Se encuentra que los efectos
cuánticos estabilizan las posiciones de las dos branas y generan la gerarquía de
forma natural si el espacio interno es plano.
En el tercer tipo de modelos, el espacio interno no tiene factor de warp y la
jerarqía se genera mediante el efecto de redshift. Al igual que en el modelo de
Randall Sundrum, la fuerza de Casimir debida a un campo de gauge en el bulk puede
estabilizar la jerarquía de forma natural.
Se concluye que en los modelos de branas con geometría no factorizable, los efectos
cuánticos son capaces de estabilizar la jerarquía naturalmente de forma relativamente
genérica.
Certain brane world scenarios can solve the hierarhy problem exploiting the fact that,
in these models, the separation between the electroweak and the Planck scales
--'the hierarchy'-- depends on the size of the extra dimensions. This size is
parmetrized by a scalar mode of the higher dimensional metric called 'the radion'.
Hence, a complete solution to the hierarchy problem requires a stabilization mechanism
that naturally fixes the radion at an appropriate value and explains why the interactions
mediated by such a scalar are not observed.
In this thesis, we consider the possibility that the Casinir energy is responsible for
stabilizing the radion and generating a large hierarchy in a natural way. We argue that,
in scenarios where the geometry is not factorizable, the quantum effects indeed can provide
a stabilization mechanism that generates naturally a large hierarchy. Specifically, we
discuss three classes of models.
The first example consists in a five dimensional scalar--tensor model bounded by two
parallel branes, where the warp factor grows like a power of the distance. The presence
of an anomalous scaling symmetry in the model allows to stabilize the moduli, which
correspond to the brane locations. A large hierarchy can be obtained even for low values
of the power. However, the generated masses for the moduli are large enough if the power
of the warp factor is of order 10 or bigger.
The second class of models consists in a space of more than five dimensions where the
additional internal space and the noncompact directions share an exponential warp factor.
In these models, the hierarchy is generated by a combination of the redshift effect and
the large volume effect. We find that the Casimir energy stabilizes the brane positions and
generate a large hierarchy if the internal space is flat.
In the third example, the internal space does not have a warp factor and the hierarhy is
generated by the redshift effect. As is the Randall Sundrum model, the Casimir force due
to a bulk gauge field can generate and stabilize a large hierarchy in a natural fashion.
We conclude that relatively generically, the quantum effects can naturally stabilize a
large hierarchy in models with a non factorizable geometry.
Lang, Andrew. "The casimir effect /." free to MU campus, to others for purchase, 1998. http://wwwlib.umi.com/cr/mo/fullcit?p9904856.
Повний текст джерелаHolmes, Christopher David. "Acoustic Casimir effect." Monterey, California. Naval Postgraduate School, 1997. http://hdl.handle.net/10945/7844.
Повний текст джерелаJacobs, David M. "Casimir Localization." Case Western Reserve University School of Graduate Studies / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=case1396608069.
Повний текст джерелаHaakh, Harald Richard. "Cavity QED with superconductors and its application to the Casimir effect." Master's thesis, Universität Potsdam, 2009. http://opus.kobv.de/ubp/volltexte/2009/3256/.
Повний текст джерелаThis thesis investigates the Casimir effect between plates made of normal and superconducting metals over a broad range of temperatures, as well as the Casimir-Polder interaction of an atom to such a surface. Numerical and asymptotical calculations have been the main tools in order to do so. The optical properties of the surfaces are described by dielectric functions or optical conductivities, which are reviewed for common models and have been analyzed with special weight on distributional properties and causality. The calculation of the Casimir energy between two normally conducting plates (cavity) is reviewed and previous work on the contribution to the Casimir energy due to the surface plasmons, present in all metallic cavities, has been generalized to finite temperatures for the first time. In the field of superconductivity, a new analytical continuation of the BCS conductivity to to purely imaginary frequencies has been obtained both inside and outside the extremely dirty limit of vanishing mean free path. The Casimir free energy calculated from this description was shown to coincide well with the values obtained from the two fluid model of superconductivity in certain regimes of the material parameters. The Casimir entropy in a superconducting cavity fulfills the third law of thermodynamics and features a characteristic discontinuity at the phase transition temperature. These effects were equally encountered in the Casimir-Polder interaction of an atom with a superconducting wall. The magnetic dipole coupling of an atom to a metal was shown to be highly sensible to dissipation and especially to the surface currents. This leads to a strong quenching of the magnetic Casimir-Polder energy at finite temperature. Violations of the third law of thermodynamics are encountered in special models, similar to phenomena in the Casimir-effect between two plates, that are debated controversely. None of these effects occurs in the analog electric dipole interaction. The results of this work suggest to reestablish the well-known plasma model as the low temperature limit of a superconductor as in London theory rather than use it for the description of normal metals. Superconductors offer the opportunity to control the dissipation of surface currents to a great extent. This could be used to access experimentally the low frequency optical response of metals, which is strongly connected to the thermal Casimir-effect. Here, differently from corresponding microwave experiments, energy and momentum are independent quantities. A measurement of the total Casimir-Polder interaction of atoms with superconductors seems to be in reach in today’s microchip-based atom-traps and the contribution due to magnetic coupling might be accessed by spectroscopic techniques
Obadia, Nathaniel. "Le modèle de Davies-Fulling et ses généralisations : un modèle pour la radiation de Hawking." Tours, 2003. http://www.theses.fr/2003TOUR4002.
Повний текст джерелаBüscher, Rauno. "Casimir forces and geometry." [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=976592533.
Повний текст джерелаRypestøl, Marianne. "Casimir effect in Randall-Sundrummodels." Thesis, Norwegian University of Science and Technology, Department of Physics, 2009. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-6353.
Повний текст джерелаFialkovskiy, Ignat. "Efeito Casimir e as propriedades óticas do grapheno." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-11032013-151501/.
Повний текст джерелаThis research is devoted to investigation of several aspects of the physics of suspended and epitaxial graphene monolayers. The description of graphene is based on the quasi--relativistic Dirac model which permits application of the methods of the Quantum Field Theory to investigation of the interaction of graphene with electromagnetic field. Basing on the path integral formalism we formulate the effective theory for EM field in presence of graphene monolayers which is governed by the polarization operator of the Dirac quasi-particles in graphene. The two main phenomena in the interaction of graphene with electromagnetic field are studied: the optical properties of graphene (the Faraday rotation in particular), and Casimir interaction between graphene samples and parallel metal. First, we study the propagation of electromagnetic waves in presence of suspended and epitaxial graphene layers. Their dynamics is governed by the modified Maxwell equations obtained from the effective theory for EM field. We calculate the reflection and transmission coefficient for linearly polarized light and investigate in detail the quantum Faraday effect in external magnetic field. In particular it is showed that the prediction of the Dirac model are in good agreement with recent experimental results on transmission and giant Faraday rotation in cyclotron resonance. New regimes are also predicted Secondly, we investigate Casimir interaction between suspended graphene films with ideal conductor. The effect is investigated both in the idealistic case (zero temperature, ideal samples) and for realistic configurations (non zero temperature and/or presence of impurities and chemical potential). For zero temperature the Casimir force between graphene and a conductor is about 2.7% of that between two ideal conductors. At the same time in the high temperature limit the effect is showed to be greatly enhanced being about 50% of that between ideal metals.
Le, Cunuder Anne. "Étude expérimentale des forces de Casimir." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEN007/document.
Повний текст джерелаThe study of density fluctuations inside confined liquid systems has received the attention of recent theoretical and experimental papers. In order to analyze the role of confinement on the statistical properties of fluctuations, we developed a highly sensitive system where the intensity of fluctuations, as well as their spatial correlation length can be simply tuned. The idea will be to enhance the role of fluctuations working close to the critical temperature Tc of a second order phase transition in a binary mixture. Indeed, the correlation length dramatically increases when one approaches the critical demixion point.The confinement is obtained by using a sphere-plane geometry with a colloidal particle attached to the cantilever of an Atomic Force Microscope (AFM). When the correlation length is comparable with the distance of confinement, Fisher and De Gennes predicted the existence of an interesting effect: the two surfaces will be submitted to either an attracting or a repelling force, depending on boundary conditions. This effect is called the critical Casimir force in reference to the quantum Casimir force resulting from the confinement of quantum fluctuations of the electromagnetic field.During this thesis, we measured the quantum Casimir force between the sphere and the plate, first in a nitrogen atmosphere and then in ethanol, showing that the developed instrument is sufficiently sensible to measure very weak force, of the same order of magnitude or even weaker than the critical Casimir force. Measurements are compared to Lifshitz theory, taking into account the finite conductivity of surfaces
Hassan, Arkan Mahmood. "Dynamical Casimir Effect Using Two Photon Absorber." Miami University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=miami1533948476369766.
Повний текст джерелаCho, Sung Nae. "Casimir Force in Non-Planar Geometric Configurations." Diss., Virginia Tech, 2004. http://hdl.handle.net/10919/11156.
Повний текст джерелаPh. D.
Mackrory, Jonathan. "The Worldline Method for Electromagnetic Casimir Energies." Thesis, University of Oregon, 2017. http://hdl.handle.net/1794/22664.
Повний текст джерелаvan, Caspel Moos. "The topological Casimir effect on a torus." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44948.
Повний текст джерелаMcCutcheon, Robert A. "Hybrid Optomechanics and the Dynamical Casimir Effect." Miami University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=miami1501191323617929.
Повний текст джерелаBorjan, Zoran. "Application of local functional theory to surface critical phenomena." Thesis, University of Bristol, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302201.
Повний текст джерелаHertlein, Johann Christopher. "Messung kritischer Casimir-Kräfte mit TIRM." [S.l. : s.n.], 2008. http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-37124.
Повний текст джерелаAzari, Arash. "Casimir effect in presence of dielectric and metallic materials." Thesis, University of Sheffield, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.531132.
Повний текст джерелаKlatt, Juliane [Verfasser], and Stefan Yoshi [Akademischer Betreuer] Buhmann. "The Casimir-Polder effect and quantum friction across timescales." Freiburg : Universität, 2017. http://d-nb.info/115468184X/34.
Повний текст джерелаObousy, Richard K. Cleaver Gerald B. "Investigation into compactifed dimensions Casimir energies and phenomenological aspects /." Waco, Tex. : Baylor University, 2008. http://hdl.handle.net/2104/5261.
Повний текст джерелаМороз, Ю. В. "Вперше виміряна сила відштовхування в ефекті Казимира-Ліфшиця". Thesis, Сумський державний університет, 2013. http://essuir.sumdu.edu.ua/handle/123456789/41113.
Повний текст джерелаGhadirian, Bahman. "A new regularization procedure for calculating the Casimir energy." View thesis, 2008. http://handle.uws.edu.au:8081/1959.7/24942.
Повний текст джерелаA thesis submitted to the University of Western Sydney, College of Health and Science, School of Biomedical and Health Sciences in fulfilment of the requirements for the degree of Doctor of Philosophy. Includes bibliographical references.
Chiu, Hsiang-Chih. "Demostration of non-additivity ans asymmetry in the lateral Casimir force." Diss., UC access only, 2009. http://proquest.umi.com/pqdweb?index=41&did=1905738741&SrchMode=1&sid=2&Fmt=7&retrieveGroup=0&VType=PQD&VInst=PROD&RQT=309&VName=PQD&TS=1270142776&clientId=48051.
Повний текст джерелаIncludes abstract. Includes bibliographical references (leaves 146-154). Issued in print and online. Available via ProQuest Digital Dissertations.
Woolf, David Nathaniel. "Near-Field Optical Forces: Photonics, Plasmonics and the Casimir Effect." Thesis, Harvard University, 2013. http://dissertations.umi.com/gsas.harvard:10812.
Повний текст джерелаEngineering and Applied Sciences
Scardicchio, Antonello. "An optical approximation to the Casimir effect and related topics." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/36811.
Повний текст джерелаIncludes bibliographical references (leaves 181-188).
In this thesis, I have studied the dependence of the Casimir force between neutral conductors on their shapes. After reducing the problem to that of finding the density of states of' an appropriate hamiltonian I studied it by using semiclassical methods. Some exemplary geometries of interest for the experiments are studied in detail.
by Antonello Scardicchio.
Ph.D.
Colombaro, Ivano. "Dynamical Casimir effect and the structure of vacuum in quantum field theory." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/10382/.
Повний текст джерелаPelisson, Sophie. "Etude d'états atomiques à proximité d'une surface massive : application à l'expérience FORCA-G." Observatoire de Paris (1667-....), 2012. https://theses.hal.science/tel-00788325.
Повний текст джерелаThis thesis presents the theoretical modeling of the experiment FORCA-G (FORce de CAsimir et Gravitation à courte distance) currently in progress at Paris Observatory. The purpose of this experiment is to measure short-range interactions between an atom and a massive surface. This interaction are of two kind : quantum electrodynamical (Casimir-Polder effect) and gravitationnal. The work presented here was to calculate atomic states in the context of the experiment such that we can predict results and performances of the experiment. This has allowed to optimize the experimental scheme both for the high-precision measurement of the Casimir-Polder effect and for the search of deviation from Newton's law of gravity predicted by unification theories
Sin, Ronia Kévin. "Casimir and dynamical interactions in membranes and model systems." Paris 7, 2014. http://www.theses.fr/2014PA077254.
Повний текст джерелаLes membranes lipidiques sont des milieux complexes qui sont soumis à des fluc-tuations thermiques donnant naissance à des interactions du type Casimir quand des objets y sont inclus. Dans cette thèse, nous nous intéressons aux interactions du type Casimir et aux interactions élastiques qui apparaissent entre objets inclus dans un milieu élastique. Dans la première partie, nous nous intéressons à deux bâtons parallèles de longueur L adsorbés sur une membrane fluide et calculons analytiquement l'interaction du type Casimir pour de faibles distances d< L. Les deux bâtons sont modélisés comme des contraintes, le long d'une ligne droite, imposées à la membrane et en particulier à sa courbure. Ceci nous permet de définir quatre type de bâton, selon que la membrane peut se tordre ou non le long ou/et perpendiculairement aux bâtons. Pour des contraintes rigides, toutes les énergies d'interactions sont attractives et proportionnelles à L/d. Deux des quatre type de bâtons définis sont équivalents ce qui conduit à six amplitudes différentes mais universelles pour les interactions de Casimir. Des conditions de répulsions peuvent être réunies pour des bâtons différents avec des contraintes molles. Des résultats numériques obtenus pour une large gamme de ratio d/L montrent que le potentiel attractif peut atteindre kBT pour d/L≃0. 2. Enfin pour des distances plus petites que dc≃ L(L//p)1/3, où lp est la longueur de persistance, deux bâtons aux extrémités fixées se courberont jusqu'à entrer en contact du fait de l'interaction de Casimir. Dans un second temps nous considérons le problème du calcul de l'interaction de Casimir pour des objets de forme arbitraire en discrétisant les contours avec des contraintes ponctuelles vue comme des inclusions ponctuelles. Nous étudions comment l'universalité émerge de cette discrétisation. Ayant introduit un cutoff et une régularisation pour le calcul de la fonction de corrélation du champ de la membrane, nous trouvons que l'universalité apparaît si (i) la distance entre les inclusions ponctuelles est inférieure au cutoff A-1 et (ii) si les objets considérés sont bien plus grands que le cutoff. Une transition brutale du régime de condition de bord discret au régime continu intervient pour δ =π/Λ dans la limite thermodynamique pour des bâtons à grande distance. Nous illustrons ces propriétés à deux dimensions pour des objets du type bâton et des objets de forme plus complexe comme des lunes. Enfin, dans un milieu élastique unidimentionnel avec une longueur de corrélation finie, ie loin des conditions critiques, et dont la dynamique suit uniquement une dynamique de relaxation, nous calculons la dépendance temporelle de la force élastique F(t) échangée par deux inclusions actives qui imposent une déformation élastique au milieu. Cette déformation est déclenchée à l'instant t = 0 par les inclusions. Nous considérons (i) des inclusions linéaires qui couplent les champs à une force finie puis (ii) des inclusions non linéaires qui impose une déformation finie au milieu. Dans le cas non linéaire, la force présente un maximum transitoire, bien plus élevé que la force à l'équilibre, et qui diverge comme ~ L2 pour des distance L inférieures à la longueur de corrélation du champs considéré. Nous calculons à la fois l'interaction de champs moyen et l'interaction de Casimir. Nous discutons également les temps caractéristiques d'établissement et de mise à l'équilibre des forces en comparant le cas linéaire et le cas non linéaire. Il est important de noter que l'existence d'un maximum transitoire dans l'établissement de la force non linéaire semble être une caractéristique des interactions élastiques médiées
Simpson, William M. R. "Surprises in theoretical Casimir physics : quantum forces in inhomogeneous media." Thesis, University of St Andrews, 2014. http://hdl.handle.net/10023/6338.
Повний текст джерелаMaia, Clóvis Achy Soares [UNESP]. "Fluxos e densidades de energia negativa em teoria quântica de campos." Universidade Estadual Paulista (UNESP), 2005. http://hdl.handle.net/11449/91855.
Повний текст джерелаFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Sabe-se já há algum tempo que a Teoria Quântica de Campos permite violações das Condições Clássicas de Energia na forma de densidades e fluxos de energia negativa. Um exemplo contundente é o efeito Casimir, onde o estado de vácuo do campo eletromagnético entre duas placas metálicas possui densidade de energia negativa. Porém, se as leis da física não colocassem restrições sobre tais violações das Condições de Energia, aparentemente seria possível usar energias negativas para, por exemplo, produzir violações macroscópicas da segunda lei da termodinâmica, da conjectura de cosmic censorship, além de se proporcionar a criação de wormholes e possíveis máquinas do tempo. Uma linha de pesquisa desenvolvida para abordar essa questão envolve as chamadas Desigualdades Quânticas, estudadas primeiramente por L.H. Ford, que são desigualdades sobre fluxos e densidades de energia negativa que impõem restrições capazes de tornar as violações acima não observáveis macroscopicamente. Nesta dissertação apresentaremos alguns exemplos de sistemas que possuem densidades ou fluxos de energia negativa, revisaremos os teoremas de Desigualdades Quânticas e discutiremos algumas de suas aplicações. Discutiremos também algumas limitações destes teoremas apresentando sistemas que não estão sujeitos a desigualdades quânticas, dos quais um exemplo é o próprio efeito Casimir. Iremos enfim propor um modelo que introduz flutuações quânticas nas condições de contorno (e.g., nas placas metálicas) do efeito Casimir, e iremos mostrar que a introdução destes efeitos de flutuação no cálculo da energia de Casimir tem por resultado impedir que violações de leis físicas macroscópicas manifeste-se nesse sistema.
Abstracts: It has been known for some time that Quantum Field Theory allows the violation of Classical Energy Conditions in the form of negative energy densities and fluxes. A remarkable exemple is the Casimir effect, where the vacuum state of the electromagnetic field between two perfectly conducting parallel plates presents negative energy density. However, if he laws of physics did not place constraints on such a violation of the Energy Conditions, it appears that it would be possible to use negative energies for producing, for example, macroscopic violation of the second law of thermodynamics, of the cosmic censorship conjecture, and also provide the creation of woemholes and time machines. A line of research wich was developed to approach this question is the so called Quantum Inequalities, first studied by L.H. Ford, which are constraints over negative energy densities and fluxes with capacity to render the above violations macroscopically unobservable. We present here some examples of systems with negative energy densities or fluxes, review the Quantum Inequalities theorems and discuss some of its applications. We also discuss some limitations of these theorems showing systems where there are no quantum inequalities, being the Casimir effect one example. At last we propose a model which introduces quantum fluctuations in the description of the boundaries conditions (e.g., the conducting plates) of Casimir effect and we'll show that the introduction of these fluctuations in the calculation of Casimir energy results in the impossibility of violation of macroscopic physical laws using Casimir configuration.
Canaguier-Durand, Antoine. "Multipolar scattering expansion for the Casimir effect in the sphere-plane geometry." Paris 6, 2011. http://www.theses.fr/2011PA066246.
Повний текст джерелаDroujinina, Viola. "On quantum reflection and the Casimir effect application to atom surface scattering /." [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=96859607X.
Повний текст джерелаUllio, Ícaro Joshua Morales. "Consequências da violação da simetria de Lorentz no Efeito Casimir." Universidade Federal da Paraíba, 2015. http://tede.biblioteca.ufpb.br:8080/handle/tede/8000.
Повний текст джерелаMade available in DSpace on 2016-03-16T11:18:29Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 836345 bytes, checksum: 048933d0a290c347efd2fa4764bbcf63 (MD5) Previous issue date: 2015-02-20
In this Dissertation we’ll consider a scalar field theory where the breaking of Lorentz symmetry is present. Basically we will adopt the Ho˘rava-Lifshtz theory. We’ll study the modifications that an anisotropy in space-time produces in the Casimir effect. Let’s deal with a massless real scalar field in two distinct situations: between parallel plates and inside a two-dimensional rectangular box. In both cases we will adopt specific boundary conditions on the field. As we shall see, the Casimir energy and force strongly depends on the parameter associated with the breaking of Lorentz symmetry.
Nesse Dissertação consideraremos uma teoria de campo escalar onde a quebra da simetria de Lorentz está presente. Basicamente adotaremos a teoria de Ho˘rava-Lifshtz. Estudaremos as modificações que uma anisotropia no espaço-tempo produzem no efeito Casimir. Vamos tratar um campo escalar real sem massa em duas situações distintas: entre placas paralelas e no interior de uma caixa bidimensional retangular. Nos dois casos adotaremos condições de contorno específicas sobre o campo. Como veremos, a energia e a força de Casimir dependem fortemente do parametro associado a quebra da simetria de Lorentz.
Lussange, Johann A. "The Casimir energy and radiative heat transfer between nanostructured surfaces." Paris 6, 2012. http://www.theses.fr/2012PA066244.
Повний текст джерелаIntravaia, Francesco. "Effet Casimir et interaction entre plasmons de surface." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2005. http://tel.archives-ouvertes.fr/tel-00009755.
Повний текст джерелаEspinosa, Jorge D. "De-wetting of cobalt thin films on sapphire." Morgantown, W. Va. : [West Virginia University Libraries], 2007. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5314.
Повний текст джерелаTitle from document title page. Document formatted into pages; contains ix, 106 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 102-105).
Maury, Axel. "Effet Casimir-Polder sur des atomes piégés." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066327/document.
Повний текст джерелаThis thesis presents the theoretical modeling of the experiment FORCA-G. The purpose of this experiment is to measure short-range interactions between trapped atoms in an optical lattice and a massive surface with a high precision. We are focused on Casimir-Polder effect induced by the surface on the atoms. The aim was to give the most possible precise prediction of atomic states. This work took the temperature effects on Casimir-Polder interaction into account, modelled the surface of the experiment. In order to solve the divergence problem due to the perturbative treatment of the atom-surface interaction, we developed a digital method for a non-perturbative treatment of the Casimir-Polder interaction and modelled the short-range atom-surface interaction by a Lennard-Jones potential. Each effect and uncertainties on the atomic states were evaluated so that we know if they could be observable or a limiting factor compared to the experiment precision. Finally we were focused on an out of thermal equilibrium situation between the miroir and environment temperature which may be induced by the lasers. We computed the correction to the Casimir-Polder potential due to this disequilibrium and evaluated the effect on the atomic states
Siria, Alessandro. "Systèmes nano électro mécanique et intéractions à l'échelle nanométrique." Grenoble 1, 2009. http://www.theses.fr/2009GRE10264.
Повний текст джерелаMicro and Nano Electro Mechanical Systems (MEMS and NEMS) are among the best candidates for the measurement of interactions at the nanoscale. Resolution in force in the range of attonewton has been successfully exploited for the weighting of single molecules or the measurement of the spin of a single electron. NEMS and MEMS are generally mechanical devices made from submicron components facing each other. When the distance between the components reaches the sub-micron scale, phenomena generally neglected during macroscopic applications have to be taken into account. For example, the interaction mechanisms between the two surfaces moving at sub-micron separations are mediated by forces that, in macroscopic devices, are often irrelevant. In this thesis work we study interaction forces between surfaces when the the gap separating them is in the range from tens of nanometers up to several micrometers. First we address the problem of hydrodynamic forces acting on micro-structures oscillating in viscous environment. We show that the effect damping of a confined fluid is depending by the gap size of the confinement cavity. We study how this confinement effect can modify the properties of the mechanical oscillator. Second we address the problem of optical forces acting on micro mechanical oscillators. Using absorption and diffraction of X-ray beams we will see that effects usually observed using visible light can also be observed using X-rays. We show that Micro and possibly Nano Electro Mechanical System can be suitable for developing new tools in the domain of Synchrotron light techniques. Finally we study the thermal radiation between surfaces when the gap is the micron and sub-micron scale where the contribution of near field components cannot be neglected. We show measurement of thermal radiation between surfaces of glass providing a comparison with the theory of thermal radiation based on stochastic electrodynamics
Laurent, Justine. "Mesures de la force de Casimir à basse température." Phd thesis, Université de Grenoble, 2010. http://tel.archives-ouvertes.fr/tel-00576595.
Повний текст джерелаCanaguier-Durand, Antoine. "Développement multipolaire de l'effet Casimir dans la géométrie sphère-plan". Phd thesis, Université Pierre et Marie Curie - Paris VI, 2011. http://tel.archives-ouvertes.fr/tel-00805047.
Повний текст джерелаKawka, Sébastien. "Moment de Casimir : effet du vide quantique sur l’impulsion d’un milieu bi-anisotrope." Grenoble, 2010. http://www.theses.fr/2010GRENY039.
Повний текст джерелаWe have presented a non-relativistic quantum electrodynamic theory for the total of an harmonic oscillator, subject to external classical fields, and coupled to the electromagnetic quantum vacuum. The most important conclusions of this work are that Casimir momentum exists and that its UV divergences are renormalized. The theory shows it to be basically a non-relativistic quantity, but that relativistic corrections are likely to be significant, much like in the Lamb shift problem. Using reasonable experimental values, we estimate a classical contribution to the momentum of approximately 5 micrometer per second and a quantum correction of 0. 1 micrometer per second. To our knowledge nor the classical contribution to magneto-electric momentum, neither the QED correction have ever been observed. We studied the case of an hydrogen atom in movement. Here the bi-anisotropy is due to the Fizeau effect and is characterize by the velocity. Thus we expect a correction proportional to the velocity, ie a mass correction. We find indeed that this is in total agreement with the mass energy equivalence principle, for temperature zero or non zero. We show the way to find the same result in the case of the Casimir energy of two atoms. We calculate then the Casimir energy of a dilute dielectric ball associated with the Van der Waals forces. We made a numerical model to compute the total energy of the ball in function of his radius. We determined the latent heat and surface tension parts. We found then a linear term that do not show up in a continuous and renormalized description of the matter, due to the neglect of short distance interactions
Reis, João Lucas Miqueleto. "Modelos análogos de gravitação semi-clássica usando circuitos supercondutores." reponame:Repositório Institucional da UFABC, 2017.
Знайти повний текст джерелаDissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Física, 2017.
Essa dissertação de mestrado tem por objetivos estudar e discutir as bases matemáticas e conceituais da teoria quântica de campos em espaços-tempos curvos (TQCEC) e analisar como podemos simular efeitos de TQCEC, como o efeito Hawking e o efeito Casimir dinâmico, usando circuitos supercondutores. Após o estudo do formalismo da relatividade geral e da TQCEC, é feita uma revisão sobre os modelos análogos de gravitação em fluidos. Em seguida analisamos a física dos chamados circuitos supercondutores e estudamos como achar análogos de efeitos de TQCEC usando tais sistemas.
This dissertation aims to study and discuss the mathematical and conceptual basis of quantum field theory in curved space-time (QFTCS) and analyse how we can simulate QFTCS effects, such as the Hawking effect and the dynamical Casimir effect, using superconducting circuits. After studying the general relativity formalism and QFTCS, a review is done on analogue models of gravitation in fluids. Then we analyse the physics of the so-called superconducting circuits and study how to find analogues of QFTCS effects using such systems.
Baumgärtel, C., and Martin Tajmar. "The Planck Constant and the Origin of Mass due to a Higher Order Casimir Effect." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2018. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-237708.
Повний текст джерелаDezael, François-Xavier. "L'Effet Casimir Dynamique et son lien avec l'Amplification Paramétrique en Optique Quantique." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2007. http://tel.archives-ouvertes.fr/tel-00165149.
Повний текст джерелаCrépin, Pierre-Philippe. "Réflexion quantique d’un paquet d’onde d’antihydrogène refroidi." Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS054.
Повний текст джерелаThe framework of this thesis is the GBAR collaboration at CERN, which aims to measure the free fall acceleration of antimatter . In this thesis, we study the quantum reflection of the antihydrogen on the detector, caused by the Casimir-Polder interaction that we calculate for different materials. We find a particularly high quantum reflection for an antihydrogen atom on a surface of liquid helium. We then present a complete description of the gravitational quantum states, mixing gravity and Casimir-Polder interaction. For this purpose, we revisit the theory of collisions in the case of the Casimir-Polder potential through a new "effective range theory", obtained after a Liouville transform. The knowledge of gravitational quantum states leads us to propose a new method of measuring free fall acceleration, by creating quantum interferences between these states. A statistical analysis of the interference pattern thus obtained is carried out, leading to an improvement in the accuracy until three orders of magnitude compared to the initial free-fall experiment. Finally, we study in detail the influence of the disorder at the level of the plate of detection, the latter being in fact not a perfect surface. We calculate the effect of this disorder on the fluctuations of the Casimir-Polder potential itself, and observe a different behavior in law for the conductivity models such as the plasma model and the Drude model