Dissertations / Theses on the topic 'Quantum optics and quantum optomechanics'
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Kelly, Stephen C. "EXPLORATION OF QUBIT ASSISTED CAVITY OPTOMECHANICS." Miami University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=miami1408097717.
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Elouard, Cyril. "Thermodynamics of quantum open systems : applications in quantum optics and optomechanics." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAY046/document.
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La thermodynamique a été développée au XIXe siècle pour décrire la physique des moteurs et autres machines thermiques macroscopiques. Depuis lors, le progrès des nanotechnologies a rendu nécessaire d'étendre ces lois, initialement pensées pour des systèmes classiques, aux systèmes obéissant à la mécanique quantique. Durant cette thèse, j'ai mis en place un formalisme pour étudier la thermodynamique stochastique des systèmes quantiques, dans lequel la mesure quantique occupe une place centrale: à l'instar du bain thermique de la thermodynamique statistique classique, la mesure est ici la source première d'aléatoire dans la dynamique. Dans un premier temps, j'ai étudié la mesure projective comme une transformation thermodynamique à part entière. J'ai montré que la mesure cause un changement incontrôlé de l'énergie du système quantique étudié, que j'ai appelé chaleur quantique, ainsi qu'une production d'entropie. Comme application de ces concepts, j'ai proposé un moteur qui extrait du travail à partir des fluctuations quantiques induites par la mesure. Ensuite, j'ai étudié les mesures généralisées, ce qui a permis de décrire des systèmes quantiques ouverts. J'ai défini les notions de travail, de chaleur, et de production d'entropie pour une réalisation unique d'une transformation thermodynamique, et retrouvé que ces quantités obéissent à des théorèmes de fluctuation. Ce formalisme m'a permis d'analyser le comportement thermodynamique de la situation canonique de l'optique quantique : un atome à deux niveaux en couplé à un laser et au vide électromagnétique. Enfin, j'ai étudié une plate-forme prometteuse pour tester la thermodynamique d'un Qubit : un système hybride optomécanique.Le formalisme développé dans cette thèse peut être d'un grand intérêt pour la communauté de thermodynamique quantique car il permet de caractériser les performances des machines thermiques quantiques et de les comparer à leurs analogues classiques. En outre, en caractérisant la mesure quantique comme un processus thermodynamique, il ouvre la voie à de nouveaux types de machines thermiques, exploitant d'une manière inédite les spécificités du monde quantiqueThermodynamics was developed in the XIXth century to provide a physical description to engines and other macroscopic thermal machines. Since then, progress in nanotechnologies urged to extend these formalism, initially designed for classical systems, to the quantum world. During this thesis, I have built a formalism to study the stochastic thermodynamics of quantum systems, in which quantum measurement plays a central role : like the thermal reservoir of standard stochastic thermodynamics, it is the primary source of randomness in the system's dynamics. I first studied projective measurement as a thermodynamic process. I evidenced that measurement is responsible for an uncontroled variation of the system's energy that I called quantum heat, and also a production of entropy. As a proof of concept, I proposed an engine extracting work from the measurement-induced quantum fluctuations. Then, I extended this formalism to generalized measurements, which allowed to describe open quantum systems (i.e. in contact with reservoirs). I defined work, heat and entropy production for single realizations of thermodynamic protocols, and retrieved that these quantities obey fluctuation theorems. I applied this formalism to the canonical situation of quantum optics, i.e. a Qubit coupled to a laser and a the vacuum. Finally, I studied a promising platform to test Qubit's thermodynamics: a hybrid optomechanical system.The formalism developed in this thesis could be of interest for the quantum thermodynamics community as it enables to characterize quantum heat engines and compare their performances to their classical analogs. Furthermore, as it sets quantum measurement as a thermodynamic process, it pave the ways to a new kind of thermodynamic machines, exploiting the specificities of quantum realm in an unprecedented way
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McCutcheon, Robert A. "Hybrid Optomechanics and the Dynamical Casimir Effect." Miami University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=miami1501191323617929.
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Seok, HyoJun. "Aspects Of Multimode Quantum Optomechanics." Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/332877.
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This dissertation aims to investigate systems in which several optical and mechanical degrees of freedom are coupled through optomechanical interactions. Multimode optomechanics creates the prospect of integrated functional devices and it allows us to explore new types of optomechanical interactions which account for collective dynamics and optically mediated mechanical interactions. Owing to the development of fabrication techniques for micro- and nano-sized mechanical elements, macroscopic mechanical oscillators can be cooled to the deep quantum regime via optomechanical interaction. Based on the possibility to control the motion of mechanical oscillators at the quantum level, we design several schemes involving mechanical systems of macroscopic length and mass scales and we explore the nonlinear dynamics of mechanical oscillators. The first scheme includes a quantum cantilever coupled to a classical tuning fork via magnetic dipole-dipole interaction and also coupled to a single optical field mode via optomechanical interaction. We investigate the generation of nonclassical squeezed states in the quantum cantilever and their detection by transferring them to the optical field. The second scheme involves a quantum membrane coupled to two optical modes via optomechanical interaction. We explore dynamic stabilization of an unstable position of a quantum mechanical oscillator via modulation of the optical fields. We then develop a general formalism to fully describe cavity mediated mechanical interactions. We explore a rather general configuration in which multiple mechanical oscillators interact with a single cavity field mode. We specifically consider the situation in which the cavity dissipation is the dominant source of damping so that the cavity field follows the dynamics of the mechanical modes. In particular, we study two limiting regimes with specific applications: the weak-coupling regime and single-photon strong-coupling regime. In the weak-coupling regime, we build a protocol for quantum state transfer between mechanical modes. In the single-photon coupling regime, we investigate the nonlinear nature of the mechanical system which generates bistability and bifurcation in the classical analysis and we also explore how these features manifest themselves in interference, entanglement, and correlation in the quantum theory.
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Tumanov, Dmitrii. "Actuation and motion detection of different micro- and nano-structures." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAY045/document.
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Cette thèse s’inscrit dans le domaine de l'opto-mécanique et propose l'utilisation de différentes techniques de mesure et de manipulation des propriétés mécaniques de nano-structures.La première partie de ce travail est dédiée aux fils photoniques. Ces objets sont des structures en GaAs en forme de cône inversé, avec une longueur d’une dizaine de µm et un diamètre inférieur au µm, contenant une couche de boîtes quantiques à l'intérieur. Nous avons démontré une méthode de réglage statique du spectre de photoluminescence de ces boîtes quantiques sensibles à la contrainte, en utilisant des nano-manipulateurs pour contraindre mécaniquement les fils. De plus, grâce à la dépendance spatiale du décalage spectral, il est possible d’établir une carte de la position des boîtes quantiques.La deuxième partie de ce travail concerne la mise en mouvement de ces fils photoniques à l’aide d’un faisceau laser modulé à la fréquence de résonance mécanique. Les mécanismes physiques à l’origine de ces effets sont présentés et discutés.Dans la troisième partie, nous présentons une méthode permettant l’observation d'oscillations mécaniques de nano-fils fins (moins de 50 nm de diamètre) en utilisant un microscope électronique à balayage. Cette méthode originale offre la possibilité de contrôler de nombreux types de structures micro et nano-électromécaniques, dont la détection du mouvement n’est pas possible optiquement en raison de la limite de diffraction de la lumière. De plus, cette méthode permet également d'agir sur les propriétés mécaniques des structures via une force de contre-réaction qui devient non négligeable pour ces structures très légères. Cela ouvre la possibilité d'études fondamentales complémentaires liées au refroidissement du mouvement mécaniqueThis thesis is related to the field of opto-mechanics and the use of different techniques for the measurement and manipulation of mechanical properties of nano-structures.First part of the work is dedicated to the photonic wires. These objects are GaAs structures with an inverted conical shape of length of the order of 10 µm and diameter of less than 1 µm, containing a layer of InAs quantum dots inside. Wide-range static stress-tuning of quantum dots photoluminescence spectrum was demonstrated using nano-manipulators to bend the wires. Additionally, owing to the spatial dependence of the spectral shift, this technique offers the possibility of QD positions mapping.The second part of this work concerns the optical actuation of these photonic wires. A laser beam focused on the wire and modulated at the mechanical resonance frequency can set the wire in motion. The physical mechanisms responsible for these effects are presented and discussed.In the third part is presented a method enabling the detection of mechanical oscillations of small (less than 50 nm in diameter) nanowires with the use of a Scanning Electron Microscope. This original method offers a possibility to detect the motion of many types of micro- and nano-electromechanical devices which are too small to be detected optically owing to light diffraction limit.Moreover, this method also affects the mechanical properties of the structures via a back-action force that becomes non-negligible for such small devices. It opens up the possibility for further fundamental studies related to cooling of the mechanical motion
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Yeo, Inah. "A quantum dot in a photonic wire : spectroscopy and optomechanics." Thesis, Grenoble, 2012. http://www.theses.fr/2012GRENY076/document.
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Dans cette thèse, nous avons étudié les propriétés optiques de boîtes quantiques InAs/GaAs contenues dans un fil photonique. Des résultats antérieurs à cette thèse ont montré que ces fils photoniques permettent d’extraire les photons avec une efficacité très élevée.Le premier résultat original de ce travail est l’observation de la dérive temporelle de la raie d’émission de la photoluminescence d’une boîte quantique. Cet effet a été attribué à la lente modification de la charge de surface du fil due à l’absorption des molécules d’oxygène présentes dans le vide résiduel du cryostat. Nous avons montré qu’une fine couche de Si3N4 permettait de supprimer cette dérive. La dérive temporelle pouvant être différente pour différentes boites quantiques, nous avons pu tirer partie de cet effet pour mettre en résonance deux boites quantiques contenues dans le même fil.Le deuxième résultat original est la mise en évidence de la modification de l’énergie d’émission d’une boîte quantique soumise à une contrainte mécanique induite par la vibration du fil. Nous avons observé que le spectre de la raie d’émission d’une boîte quantique s’élargit considérablement lorsque le fil est mécaniquement excité à sa fréquence de résonance. A l’aide d’une illumination stroboscopique synchronisée avec l’excitation mécanique, nous avons pu reconstruire l’évolution du spectre d’une boîte quantique au cours d’une période de la vibration mécanique. L’amplitude de l’oscillation spectrale de la raie de luminescence dépend de la position de la boîte dans le fil à cause d’un très fort gradient de contrainte. En utilisant deux modes d’oscillation mécanique de polarisations linéaires et orthogonales, nous pouvons extraire une cartographie complète de la position des boîtes quantiques à l’intérieur du fil. Enfin, grâce à ce gradient, on peut, dans certains cas, trouver une position du fil pour laquelle deux boites quantiques peuvent être amenées en résonanceIn the framework of this thesis, single InAs/GaAs quantum dot devices were studied by optical means. Starting with a general description of self-assembled InAs QDs, two types of single QD devices were presented. The first approach was a tapered GaAs photonic wire embedding single InAs QDs whose efficiency as a single photon source was previously shown to be 90%. We investigated several optical properties of the single QDs. The charged and neutral states of the QD were identified and selectively excited using quasi-resonant excitation.The first original result of this thesis is the observation of a continuous temporal blue-drift of the QD emission energy. We attributed this blue drift to oxygen adsorption onto the sidewall of the wire, which modified the surface charge and hence the electric field seen by the QD. Moreover, we demonstrated that a proper coating of the GaAs photonic nanowire surface suppressed the drift. The temperature effect on this phenomenon revealed an adsorption peak around 20K, which corresponds to the adsorption of oxygen on GaAs. This observation is in good agreement with previous temperature studies with a tapered photonic wire. This was the first study of the spectral stability of photonic wires embedding QDs, crucial for resonant quantum optics experiments. As an alternative, we took advantage of this temporal drift to tune QD emission energies. In a controlled way, we tuned into resonance two different QDs which were embedded in the same photonic nanowire. In the last part of this work, we studied the influence of the stress on single QDs contained in a trumpet-like GaAs photonic wire. The main effect of stress is to shift the luminescence lines of a QD. We applied the stress by exciting mechanical vibration modes of the wire. When the wire is driven at its the mechanical resonance the time-integrated photoluminescence spectrum is broaden up to 1 meV owing to the oscillating stress, The measured spectral modulation is a first signature of strain-mediated coupling between a mechanical resonator and embedded QD single light emitter. With a stroboscopic technique, we isolated a certain phase of the oscillating wire and thereby selected a value of QD emission energies. As a highlight of our study, we managed to bring two different QDs contained in the same wire into resonance by controlling their relative phase. In addition, we could extract the 2D spatial positioning of embedded QDs from the spectral shifts observed for two orthogonal mechanical polarizations.. The investigation of the strain-mediated tuning of QDs can, therefore, be an effective tool to explore the QD positions without destroying the sample
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Mirza, Imran. "Storage, Interference and Mechanical Effects of Single Photons in Coupled Optical Cavities." Thesis, University of Oregon, 2014. http://hdl.handle.net/1794/18525.
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We study different phenomena associated with single-photon propagation in optical cavities coupled through optical fibers. We first address the issue of storing and delaying single-photon wavepackets in an array of microcavities. This has possible applications in developing reliable and efficient quantum repeaters that will be utilized
in building long distance quantum networks. Second, we investigate a Hong-Ou-Mandel (HOM) type of interference between two photons that are produced in two coupled atom-cavity systems. The HOM effect in this setup can test the degree of indistinguishability between photons when they are stored inside cavities. This part of the dissertation also includes the study of entanglement between atoms, cavities and atom-cavity systems induced by the photons. Finally, we focus on single-photon interactions with a tiny movable mirror in the context of quantum optomechanics. We investigate how the mechanical motion of the mirror leaves its imprints on the optical spectrum of the photon
This dissertation includes previously published and unpublished co-authored material.10000-01-01
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Abbs, Charlotte. "Quantum dynamics of non-linear optomechanical systems." Thesis, University of Nottingham, 2014. http://eprints.nottingham.ac.uk/27692/.
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This thesis explores the dynamics of optomechanical systems, which use radiation pressure to couple together optical and mechanical modes. Such systems display dynamics ranging from the quantum to the classical, with a variety of applications including ground state cooling and precision measurements. In this thesis two different geometries are presented for such a system in the form of the ‘reflective’ and ‘dispersive’ systems. Different aspects of the dynamics are investigated numerically and analytically. Firstly the reflective system is introduced, which consists of a cavity formed from a fixed and a moveable mirror. The optical frequency of the cavity couples linearly to the moveable mirror’s position. This geometry is explored as the cavity is driven by a laser, revealing a range of dynamical states in the mirror as the drive frequency is varied. An alternative geometry is presented in the form of the dispersive optomechanical system. Two fixed mirrors with a partially transmitting membrane at the centre provide a cavity supporting two optical modes, that couple approximately linearly or quadratically to the membrane position, depending on where the membrane is fixed. The system is explored in both linear and quadratic coupling regimes. Quadratic coupling is explored for a single optical mode by selecting a high tunnelling rate through the membrane. The dynamics of the membrane are explored via a similar set of techniques to those applied to the reflective system. Linear coupling for two optical modes is explored in the regimes of blue and red detuning. First resolved sideband cooling is explored, providing an alternative approach ground state cooling (which has been explored for the reflective case). Finally, strongly driving the system over a range of coupling strengths induces classical behaviour, extending from limit cycle oscillations to chaotic motion.
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Monsel, Juliette. "Thermodynamique quantique et optomécanique." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAY051.
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La thermodynamique a été développée au XIXème siècle pour étudier les machines à vapeur exploitant les transformations cycliques d'un fluide calorifique pour extraire de la chaleur de bains thermiques et la convertir en travail, éventuellement stocké dans une batterie. Cette discipline appliquée a finalement permis d'élaborer des concepts fondamentaux tels que l'irréversibilité. La thermodynamique quantique vise à revisiter ces résultats lorsque les fluides calorifiques, bains et batteries deviennent des systèmes quantiques. Ses résultats sont encore essentiellement théoriques.Cette thèse propose donc des méthodes de mesure in situ du travail, directement dans la batterie, et démontre le potentiel de deux plateformes pour ouvrir la voie à l'exploration expérimentale de ce domaine en plein essor.J'ai tout d'abord étudié les systèmes hybrides optomécaniques qui se composent d'un qubit couplé au champ électromagnétique d'une part, et à un résonateur mécanique d'autre part. La fréquence de transition du qubit est modulée par les vibrations du système mécanique, qui exerce ainsi une force sur le système. Le degré de liberté mécanique échange du travail avec le qubit et se comportant donc comme une batterie dispersive, c'est-à-dire dont la fréquence propre est très différente de celle de la transition du qubit. Enfin, le champ électromagnétique joue le rôle du bain. J'ai d'abord montré que les fluctuations d'énergie mécanique de la batterie sont égales aux fluctuations du travail, ce qui permet de mesurer directement l'entropie produite. En conséquence, les systèmes hybrides optomécaniques sont prometteurs pour tester expérimentalement les théorèmes de fluctuations dans un système quantique ouvert. Par ailleurs, j'ai étudié la conversion d'énergie optomécanique. J'ai montré qu'un système hybride optomécanique peut être considéré comme une machine thermique autonome et réversible permettant aussi bien de refroidir le résonateur mécanique que de construire un état cohérent de phonons en partant du bruit thermique.Par ailleurs, j'ai montré qu'il est possible de réaliser un moteur quantique à deux temps extrayant du travail d'un bain unique, non thermique. Le qubit se trouve dans un guide d'ondes unidimensionnel et la batterie est le mode du guide de même fréquence que la transition du qubit. Il s'agit donc d'une batterie résonante, contrairement au cas précédent. Premièrement, le qubit est couplé au bain ingéniéré, source d'énergie et de cohérence, qui le fait relaxer dans une superposition expérimentalement contrôlable d'états d'énergie. Deuxièmement, le bain est déconnecté et du travail est extrait en couplant qubit à un champ cohérent résonant. Ce type de système, appelé atome unidimensionnel, peut être réalisé avec des circuits supraconducteurs ou semi-conducteurs. La cohérence de l'état du qubit améliore les performances de ce moteur à la fois dans le régime classique, où un grand nombre de photons est injecté dans la batterie, et dans le régime quantique des petits nombres de photons.Cette thèse met en évidence le potentiel des systèmes hybrides optomécaniques et des atomes unidimensionnels pour explorer expérimentalement d'une part, l'irréversibilité et les théorèmes de fluctuations dans les systèmes quantiques ouverts, et d'autre part, le rôle de la cohérence dans l'extraction de travailThermodynamics was developed in the 19th century to study steam engines using the cyclical transformations of a working substance to extract heat from thermal baths and convert it into work, possibly stored in a battery. This applied science eventually led to the development of fundamental concepts such as irreversibility. Quantum thermodynamics aims at revisiting these results when the working substances, baths and batteries become quantum systems. Its results are still mainly theoretical. This thesis therefore propose methods to measure work in situ, directly inside the battery, and demonstrate the potential of two platforms to pave the way to the experimental exploration of this fast-growing field.First, I studied hybrid optomechanical systems which consist of a qubit coupled to the electromagnetic field on the one hand, and to a mechanical resonator on the other hand. The qubit's transition frequency is modulated by the vibrations of the mechanical system that exerts in this way a force on the qubit. The mechanical degree of freedom exchanges work with the qubit and therefore behaves like a dispersive battery, i.e. whose natural frequency is very different from the one of the qubit's transition. Finally, the electromagnetic field plays the role of the bath. I showed that the fluctuations of the mechanical energy are equal to the fluctuations of work, which allows the direct measurement of entropy production. As a result, hybrid optomechanical systems are promising for experimentally testing fluctuation theorems in open quantum systems. In addition, I studied optomechanical energy conversion. I showed that a hybrid optomechanical system can be considered as an autonomous and reversible thermal machine allowing either to cool the mechanical resonator or to build a coherent phonon state starting from thermal noise.Secondly, I showed that a two-stroke quantum engine extracting work from a single, non-thermal, bath can be made. The qubit is embedded in a one-dimensional waveguide and the battery is the waveguide mode of same frequency as the qubit's transition. Therefore, this is a resonant battery, unlike in the previous case. First, the qubit is coupled to the engineered bath, source of energy and coherence, that makes it relax in a experimentally controllable superposition of energy states. Secondly, the bath is disconnected and work is extracted by driving the qubit with a resonant coherent field. This kind of system, called one-dimensional atom, can be implemented in superconducting or semiconducting circuits. The coherence of the qubit's state improves the performances of this engine both in the regime of classical drive, where a large number of photons is injected in the battery, and in the quantum drive regime of low photon numbers.This thesis evidences the potential of hybrid optomechanical systems and one-dimensional atoms to explore experimentally on the one hand, irreversibility and fluctuation theorems, and on the other hand, the role of coherence in work extraction
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Park, Young-Shin 1972. "Radiation pressure cooling of a silica optomechanical resonator." Thesis, University of Oregon, 2009. http://hdl.handle.net/1794/10559.
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xi, 125 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 dissertation presents experimental and theoretical studies of radiation pressure cooling in silica optomechanical microresonators where whispering gallery modes (WGMs) are coupled to thermal mechanical vibrations. In an optomechanical system, circulating optical fields couple to mechanical vibrations via radiation pressure, inducing Stokes and anti-Stokes scattering of photons. In analogy to laser cooling of trapped ions, the mechanical motion can in principle be cooled to its ground state via the anti-Stokes process in the resolved-sideband limit, in which the cavity photon lifetime far exceeds the mechanical oscillation period. Our optomechanical system is a slightly deformed silica microsphere (with a diameter 25-30 μm ), featuring extremely high Q -factors for both optical ( Q o ∼ 10 8 ) and mechanical ( Q m ∼ 10 4 ) systems. Exploiting the unique property of directional evanescent escape in the deformed resonator, we have developed a free-space configuration for the excitation of WGMs and for the interferometric detection of mechanical displacement, for which the part of input laser that is not coupled into the microsphere serves as a local oscillator. Measurement sensitivity better than 5 × 10 -18 m /[Special characters omitted.] has been achieved. The three optically active mechanical modes observed in the displacement power spectrum are well described by finite element analysis. Both radiation pressure cooling and parametric instabilities have been observed in our experiments. The dependence of the mechanical resonator frequency and linewidth on the detuning as well as the intensity of the input laser show excellent agreement with theoretical calculations with no adjustable parameters. The free-space excitation technique has enabled us to combine resolved sideband cooling with cryogenic cooling. At a cryogenic temperature of 1.4 K, the sideband cooling leads to an effective temperature as low as 210 m K for a 110 MHz mechanical oscillator, corresponding to an average phonon occupation of 37, which is one of the three lowest phonon occupations achieved thus far for optomechanical systems. The cooling process is limited by ultrasonic attenuation in fused silica, which should diminish when bath temperature is further lowered, with a 3 He cryostat, to a few hundred millikelvin. Our experimental studies thus indicate that we are tantalizingly close to realizing the ground-state cooling for the exploration of quantum effects in an otherwise macroscopic mechanical system.
Committee in charge: Michael Raymer, Chairperson, Physics; Jens Noeckel, Member, Physics; Hailin Wang, Member, Physics; Paul Csonka, Member, Physics; Jeffrey Cina, Outside Member, Chemistry
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Siqueira, Maicon Zaniboni 1986. "O campo eletromagnético quantizado submetido a ruído e acoplado a um oscilador mecânico." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/277338.
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Orientador: Antonio Vidiella BarrancoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin
Made available in DSpace on 2018-08-20T20:42:28Z (GMT). No. of bitstreams: 1 Siqueira_MaiconZaniboni_M.pdf: 1258175 bytes, checksum: 2b8416f748d7b0825f2c173a2cf99c66 (MD5) Previous issue date: 2012
Resumo: Neste projeto será investigada a influência de ruído no processo de interação da radiação (campo quantizado) com a matéria (sistema mecânico mesoscópico). Consideraremos o modo do campo confinado em uma cavidade de alto fator de qualidade com um espelho fixo e o outro espelho móvel, este tratado como um oscilador mecânico suscetível à pressão de radiação do campo da cavidade. Investigaremos a dinâmica do sistema na situação em que o modo do campo confinado estará submetido a um ruído causando perda de coerência de fase
Abstract: In this project we will investigate the influence of noise in the process of interaction of radiation (quantized field) with the matter (mesoscopic mechanical system). We will consider the mode field confined in a cavity of high quality factor with a fixed mirror and one moving mirror, this treated as a mechanical oscillator susceptible to radiation pressure from cavity field. We will investigate the system dynamics in the situation that the confined mode eld is submitted to noise causing loss of phase coeherence
Mestrado
Física
Mestre em Física
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Neumeier, Lukas. "Novel regimes of quantum optomechanics." Doctoral thesis, Universitat Politècnica de Catalunya, 2018. http://hdl.handle.net/10803/620785.
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In everyday life the impact of light on the motion of mechanical objects is negligible. However, modern experiments making use of high quality optical resonators are able to observe significant effects originating from the forces associated with photons on small mechanical systems. The common feature of these systems is the dependence of the optical resonance frequency on the position of the mechanical object, laying the framework of optomechanics. Many interesting regimes have been explored which allow for photon-light entanglement, laser cooling of motion, generation of squeezed states of light, and even the detection of gravitational waves. Interestingly, the optomechanical interaction is so generic that its underlying concepts and derived insights can be generally applied to a large variety of systems, as we will see in this thesis.
In Chapter 1, we provide a brief overview of key concepts and results from the field of optomechanics, before going on to discuss the novel regimes and applications that we have identified and proposed.
In Chapter 2, we theoretically investigate results from a couple of experiments, that were previously not well-understood. These experiments trap dielectric nano-particles through an optical resonator mode and observe that the intensities experienced by the particles are strongly reduced compared to a conventional optical tweezer trap. We find that these systems can be fully described by a simple optomechanical toy model and derive that the optical potential inside resonators can approach a nearly perfect square well. This potential can be dynamically reshaped by changing the driving laser frequency and we find a dramatic reduction of intensities seen by the trapped particle, which could significantly increase the range of systems to which optical trapping can be applied. These results are quite remarkable and should have important implications for future trapping technologies.
In Chapter 3, we recognize that a major trend within the field of cavity QED is to attain the strong coupling regime. Additional rich dynamics can occur by considering the atomic motional degree of freedom. In particular, we show that such a system is a natural candidate to explore the single-photon optomechanical strong coupling regime of quantum optomechanics, but where the motional frequency cannot be resolved by the cavity. We show that this regime can result in a number of remarkable phenomena, such as strong entanglement between the atomic wave-function and the scattering properties of single incident photons, or an anomalous heating mechanism of atomic motion.
In Chapter 4 we show that an atom trapped in and coupled to a cavity constitutes an attractive platform for realizing the optomechanical single-photon strong coupling regime with resolved mechanical sidebands. Realizing this regime is a major goal within the field of optomechanics, as it would enable the deterministic generation of non-classical states of light. However, this regime is difficult to achieve with conventional mechanical systems due to their small zero-point motions. As an example, we show that optomechanically-induced photon blockade can be realized in realistic setups, wherein non-classical light is generated due to the interaction of photons with the atomic motion alone.En la vida cotidiana, el impacto de la luz sobre el movimiento de los objetos mecánicos es insignificante. Sin embargo, los experimentos modernos que usan resonadores ópticos de alta calidad son capaces de observar efectos significativos que se originan de las fuerzas asociadas con los fotones en pequeños sistemas mecánicos. La característica común de estos sistemas es la dependencia de la frecuencia de resonancia óptica en la posición del objeto mecánico, que establece el campo de la optomecánica. Se han explorado muchos regímenes interesantes que permiten el entrelazamiento de fotones, el enfriamiento del movimiento por láser, la generación de estados de luz comprimidos e incluso la detección de ondas gravitacionales. Curiosamente, la interacción optomecánica es tan genérica que sus conceptos subyacentes y sus profundas consecuencias pueden aplicarse generalmente a una gran variedad de sistemas, como veremos en esta tesis. En el Capítulo 1, proporcionamos una breve descripción de los principales conceptos y resultados del campo de la optomecánica, antes de pasar a analizar los nuevos regímenes y aplicaciones que hemos identificado y propuesto. En el Capítulo 2, investigamos teóricamente los resultados de un par de experimentos que antes no se entendían bien. Estos experimentos atrapan nanopartículas dieléctricas a través de un modo de un resonador óptico y observan que las intensidades experimentadas por las partículas se reducen considerablemente en comparación con una trampa de pinzas ópticas convencional. Encontramos que estos sistemas se pueden describir completamente mediante un modelo optomecánico de juguete simple y demostramos que el potencial óptico dentro de los resonadores puede aproximarse a un pozo cuadrado casi perfecto. Este potencial se puede modificar dinámicamente cambiando la frecuencia de entrada del láser y encontramos una reducción drástica de las intensidades vistas por la partícula atrapada, lo que podría aumentar significativamente el rango de sistemas a los que se puede aplicar el atrapamiento óptico. Estos resultados son bastante notables y deberían tener implicaciones importantes para las futuras tecnologías de atrapamiento. En el Capítulo 3, reconocemos que una tendencia importante en el campo de la electrodinámica cuántica de cavidades (del inglés, "cavity QED") es lograr un régimen de acoplamiento fuerte. Se pueden producir dinámicas adicionales al considerar el grado de libertad de movimiento atómico. En particular, mostramos que dicho sistema es un candidato natural para explorar el régimen de acoplamiento fuerte optomecánico de un único fotón en optomecánica cuántica, pero donde la frecuencia de movimiento no puede ser resuelta por la cavidad. Mostramos que este régimen puede dar lugar a una serie de fenómenos notables, como un fuerte entrelazamiento entre la función de onda atómica y las propiedades de dispersión de los fotones incidentes individuales, o un mecanismo de calentamiento anómalo del movimiento atómico. En el Capítulo 4 mostramos que un átomo atrapado y acoplado a una cavidad constituye una plataforma atractiva para obtener el régimen de acoplamiento fuerte optomecánico con un único fotón y con bandas laterales mecánicas resueltas. La obtención de este régimen es un objetivo principal en el campo de la optomecánica, ya que permitiría la generación determinista de estados de luz no clásicos. Sin embargo, este régimen es difícil de lograr con los sistemas mecánicos convencionales debido a sus pequeños movimientos de punto cero. Como ejemplo, mostramos que el bloqueo de fotones inducido de forma mecánica puede realizarse en configuraciones realistas, donde la luz no clásica se genera solamente debido a la interacción de fotones con el movimiento atómico.
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Lörch, Niels [Verfasser]. "Laser theory for quantum optomechanics / Niels Lörch." Hannover : Technische Informationsbibliothek und Universitätsbibliothek Hannover (TIB), 2015. http://d-nb.info/1080269193/34.
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Garrido, Mauricio. "Quantum Optics in Coupled Quantum Dots." Ohio University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1273589966.
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Gao, Xuesong. "Quantum Nonlinear Optics." University of Dayton / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1564662783494271.
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Stock, Ryan. "Silicon-based quantum optics and quantum computing." Thesis, Cardiff University, 2018. http://orca.cf.ac.uk/111871/.
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In this thesis is presented a brief review of quantum computing, the DiVincenzo criteria, and the possibility of using a solid state system for building a quantum computing architecture. Donor electron systems in silicon are discussed, before chalcogen, \deep", double donors are suggested as a good candidate for fulfilment of the criteria; the optically driven Stoneham proposal, where the spin-spin interaction between two donor electron spin qbits is mediated by the optically controlled, excited, state of a third donor electron, forms the basis of this [1]. Coherence lifetimes are established as a vital requirement of a quantum bit, but radiative lifetimes must also be long. If the spin-spin interaction between qbits is decreased, or turned off, by the de-excitation of the mediating donor electron then the coherence of the qbit is rendered irrelevant; de-excitation will ruin quantum computations that depend upon an interaction that only happens when the mediating electron is in an excited state. Effective mass theory is used to estimate excited state donor, 2P, wavefunctions for selenium doped silicon, and recent Mott semiconductor to metal transition doping data [2] is used to scale the spatial extent of the 1S(A1) ground state wavefunction. Using these wavefunctions, the expected radiative lifetimes are then calculated, via Fermi's golden rule, to be between 9 ns and 17 ns for the 2P0 state, and 12 ns to 20 ns for the 2P_1 state. Fourier Transform InfraRed (FTIR) absorbance spectroscopy is used to determine the optical transitions for selenium donors in silicon, this has allowed agreement between literature, measured, and effective mass theory energy values for the particular samples measured. FTIR time resolved spectroscopy has then been used to measure the radiative emission spectrum of selenium doped silicon samples at 10-300K, following a 1220 nm laser pulse. Fitting to the exponentially decaying emission data, selenium radiative lifetimes as long as 80 ns are found; for the 2P0 to 1S(A1) transition in an atomic selenium donor complex at 10K. A factor of between 4 and 8 agreement is found between calculated and measured radiative lifetimes. This offers the possibility of nanosecond scale donor electron coherence times for chalcogen dopants in silicon.
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Bocquillon, Erwann. "Electron quantum optics in quantum Hall edge channels." Paris 6, 2012. http://www.theses.fr/2012PA066692.
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Cette thèse est consacrée à la manipulation d'excitations mono-électroniques dans un conducteur quantique balistique, par l'implémentation d'expériences d'optique quantique électronique avec la résolution d'une charge élémentaire. Une capacité mésoscopique produit à la demande des excitations monoélectroniques dans le canal de bord externe de l'effet Hall quantique. Nous mesurons les fluctuations de courant après partitionnement des excitations sur une lame séparatrice électronique, dans un analogue de l'expérience de Hanbury-Brown & Twiss, afin de révéler les excitations neutres (paires électron/trou) qui peuvent accompagner la charge produite. Les excitations thermiques dans la mer de Fermi sont alors responsables d'interférences à deux particules qui permettent d'obtenir des informations sur la distribution en énergie des quasiparticules émises par la source. A l'aide de deux sources indépendantes et synchronisées, nous générons deux quasi-particules indiscernables, qui interfèrent sur une lame séparatrice dans un analogue de l'expérience de Hong-Ou-Mandel. La visibilité de ce phénomène est possiblement limité par la décohérence des paquets d'ondes électroniques par interaction avec l'environnement, notamment les autres canaux de bords. En mesurant le couplage capacitif entre deux canaux de bords co-propageant, nous caractérisons les effets de l'interaction coulombienne et mettons en évidence un mode neutre de propagation. Ces expériences constituent les premières implémentations d'expériences d'optique quantique électronique avec des charges uniques, et permettent d'envisager des expériences plus complexes comme la tomographie d'un paquet d'onde mono-électroniqueThis thesis is devoted to the implementation of quantum optics experiments in a ballistic quantum conductor, with single charge resolution. A mesoscopic capacitor produces on-demand single-electron excitations in the outermost edge channel of quantum Hall effect. We measure current fluctuations after partitioning of excitations on an electronic beamsplitter, in analogy with the Hanbury-Brown & Twiss experiment, so as to unveil neutral excitations (electron/holes pairs) that can accompany the emission of the charge. Thermal excitations in the Fermi sea are then responsible for two-particle interferences that yield information on the energy distribution of the generated quasiparticles. Using two independent and synchronized sources, we generate two indistinguishable quasiparticles that interfere on a beamsplitter as in the Hong-Ou-Mandel experiment. The visibility of this phenomenon could be limited by decoherence of the wavepackets due to interactions with the environment and especially with other co-propagating edge channels. By measuring the capacitive coupling between two co-propagating edge channels, we characterize the effects of Coulomb interaction on propagation and highlight a neutral mode of propagation. These experiments constitute the first implementations of electron quantum optics experiments with single charges. They pave the way to more complex experiments such as the tomography of a mono-electronic wavepacket
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Restrepo, Juan Sebastián. "Theory of quantum optomechanics with unconventional nonlinear coupling schemes." Paris 7, 2014. http://www.theses.fr/2014PA077228.
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Ces dernières années la zoologie de systèmes quantiques apprivoisés a vu l'entrée d'un nouveau membre. Dans le domaine des cavités optomécaniques on a démontré qu'il est possible d'amener des résonateurs micro et nanométriques vers leur état quantique fondamental. Ce fait est rendu possible par la capacité de ces cavités à refroidir optiquement les fluctuations browniennes des degrés de liberté mécaniques. Nous étudions des mécanismes non conventionnels de refroidissement optique dans des cavités optomécaniques. En particulier nous discutons comment les forces photothermiques (ou bolométriques) pourraient permettre d'atteindre l'état quantique fondamental d'un résonateur mécanique, et ce dans des régimes de paramètres où le refroidissement usuel par pression de radiation est limité. D'autre part la maturité expérimentale des cavités optomécaniques •Permet aujourd'hui d'explorer des régimes de couplage fort où un seul photon est suffisant pour perturber le résonateur mécanique au delà de ses fluctuations de point zéro. Suivant cette tendance nous présentons nos prédictions théoriques concernant un système qui combine l'électrodynamique quantique de cavité et l'optomécanique quantique. Nous démontrons que l'introduction d'un atome artificiel à deux niveaux dans la cavité optomécanique mène à des régimes de refroidissement et d'amplification inédits. Par ailleurs nous montrons comment la non-linéarité intrinsèque du système à deux niveaux permet d'atteindre des états non-classiques du résonateur mécaniqueIn recent years the zoology of tamed quantum systems has witnessed the arrival of a new member. In the field of optomechanical cavities it has been proven that it is possible to lead micro and nano mechanical resonators to their vibrational quantum ground state. This feat is made possible by the ability of optomechanical resonators to optically cool down the brownian motion of the mechanical degrees of freedom. We study the cooling mechanisms in optomechanical cavities subject to unconventional coupling schemes. In particular we discuss how pfiotothermal cooling leads the mechanical resonator to its ground state in regimes of parameters for which the more usual radiation pressure based cooling is unable to quench effectively enough the thermal brownian motion. On the other hand the maturity of experimental optomechanics has opened the path for the exploration of strong coupling regimes where a single photon is enough to modify the mechanical properties beyond the zero point fluctuations. Following this trend we present as well our predictions for a system combining quantum electrodynamics and quantum optomechanics. We show that by introducing an artificial two level atom inside the optomechanical cavity the cooling and amplification of mechanical motion are greatly modified. We also show how the intrinsic non-linearity of the artificial atom leads to non-classical states of the mechanical resonator
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Malz, Daniel Hendrik. "Periodic driving and nonreciprocity in cavity optomechanics." Thesis, University of Cambridge, 2019. https://www.repository.cam.ac.uk/handle/1810/283253.
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Part I of this thesis is concerned with cavity optomechanical systems subject to periodic driving. We develop a Floquet approach to solve time-periodic quantum Langevin equations in the steady state, show that two-time correlation functions of system operators can be expanded in a Fourier series, and derive a generalized Wiener-Khinchin theorem that relates the Fourier transform of the autocorrelator to the noise spectrum. Weapply our framework to optomechanical systems driven with two tones. In a setting used to prepare mechanical resonators in quantum squeezed states, we nd and study the general solution in the rotating-wave approximation. In the following chapter, we show that our technique reveals an exact analytical solution of the explicitly time-periodic quantum Langevin equation describing the dual-tone backaction-evading measurement of a single mechanical oscillator quadrature due to Braginsky, Vorontsov, and Thorne [Science 209, 547 (1980)] beyond the commonly used rotating-wave approximation and show that our solution can be generalized to a wide class of systems, including to dissipatively or parametrically squeezed oscillators, as well as recent two-mode backaction-evading measurements. In Part II, we study nonreciprocal optomechanical systems with several optical and mechanical modes. We show that an optomechanical plaquette with two cavity modes coupled to two mechanical modes is a versatile system in which isolators, quantum-limited phase-preserving, and phase-sensitive directional ampliers for microwave signals can be realized. We discuss the noise added by such devices, and derive isolation bandwidth, gain bandwidth, and gain-bandwidth product, paving the way toward exible, integrated nonreciprocal microwave ampliers. Finally, we show that similar techniques can be exploited for current rectication in double quantum dots, thereby introducing fermionic reservoir engineering. We verify our prediction with a weak-coupling quantum master equation and the exact solution. Directionality is attained through the interference of coherent and dissipative coupling. The relative phase is tuned with an external magnetic eld, such that directionality can be reversed, as well as turned on and off dynamically.
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Ekert, Artur Konrad. "Correlations in quantum optics." Thesis, University of Oxford, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293479.
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Htoon, Han. "Studies on quantum coherence phenomena of self-assembled quantum dots." Access restricted to users with UT Austin EID Full text (PDF) from UMI/Dissertation Abstracts International, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3037502.
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Dynes, James Francis. "Quantum optics in intersubband transitions in semiconductor quantum wells." Thesis, Imperial College London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.413944.
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Pope, Damian. "Contrasting quantum mechanics to local hidden variables theories in quantum optics and quantum information science /." [St. Luica, Qld.], 2002. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16765.pdf.
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Dorier, Vincent. "Quantum theory of light in linear media : applications to quantum optics and quantum plasmonics." Thesis, Bourgogne Franche-Comté, 2020. http://www.theses.fr/2020UBFCK006.
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Nous développons une méthode de quantification du champ électromagnétique en interaction linéaire avec les milieux passifs d'une part, et les milieux actifs (plasmoniques) d'autre part. Cette méthode repose sur la construction d'une structure Hamiltonienne compatible avec les équations de Maxwell, puis sur un principe de correspondence et la définition d'un espace de Fock des états quantiques. Nous utilisons les résultats de la théorie quantique pour étudier la propagation de photons dans des environnements diéléctriques et l'émission de plasmons uniquesWe develop a method of quantization of the electromagnetic field interacting with passive media on one hand, and active (plasmonic) media on the other hand. This method relies on the construction of a Hamiltonian structure compatible with the Maxwell equations, and then on a principle of correspondence and the definition of a Fock space of quantum states. We use the results of the quantum theory to study the propagation of photons in dielectric environments and the emission of single plasmons
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Liu, Xunmimg. "Nonlinear dynamics in quantum optics /." St. Lucia, Qld, 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17835.pdf.
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Hessmo, Björn. "Quantum optics in constrained geometries." Doctoral thesis, Uppsala University, Department of Quantum Chemistry, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-1208.
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When light exhibits particle properties, and when matter exhibits wave properties quantum mechanics is needed to describe physical phenomena.
A two-photon source produces nonmaximally entangled photon pairs when the source is small enough to diffract light. It is shown that diffraction degrades the entanglement. Quantum states produced in this way are used to probe the complementarity between path information and interference in Young's double slit experiment.
When two photons have a nonmaximally entangled polarization it is shown that the Pancharatnam phase is dependent on the entanglement in a nontrivial way. This could be used for implementing simple quantum logical circuits.
Magnetic traps are capable of holding cold neutral atoms. It is shown that magnetic traps and guides can be generated by thin wires etched on a surface using standard nanofabrication technology. These atom chips can hold and manipulate atoms located a few microns above the surface with very high accuracy. The potentials are very versatile and allows for highly complex designs, one such design implemented here is a beam splitter for neutral atoms. Interferometry with these confined de Broglie is also considered. These atom chips could be used for implementing quantum logical circuits.
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Rippin, Michael Andrew. "Quantum optics of tailored cavities." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242050.
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D'Arcy, Michael Brendan. "Quantum chaos in atom optics." Thesis, University of Oxford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249527.
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Linington, Ian. "Quantum optics with dynamic environments." Thesis, University of Sussex, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.442428.
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Chille, Vanessa. "Quantum optics with structured light." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066358/document.
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La présente thèse a pour objectif d'analyser la lumière structurée non-classique et ses caractéristiques. L'optique quantique et la lumière structurée sont deux sujets qui font l'objet d'examens nombreux. Ils sont néanmoins rarement examinés en combinaison. Les propriétés quantiques de la lumière structurée sont moins bien étudiées qu'ils devraient l'être. Par la lumière structurée nous entendons les champs lumineux qui montrent une structure transverse complexe de l'intensité, la phase ou la polarisation. Nous voulons lier les deux sujets de l'optique quantique et la lumière structurée dans la présente thèse. Dans ce but, nous générons expérimentalement des champs lumineux structurés non-classiques. En particulier, nous réalisons une expérience qui permet de générer des faisceaux vectoriels vectoriels - c'est-à-dire des faisceaux lumineux dont l'état de polarisation présente une structure transverse complexe - qui montrent une réduction du bruit quantique. En outre, nous étudions théoriquement les propriétés spatiales de faisceaux lumineux, ainsi que leur bruit. Plus spécifiquement, nous analysons l'incertitude quantique dans la largeur d'un faisceau lumineux. Pour prouver la faisabilité de la vérification expérimentales de nos résultats théoriques, nous réalisons des simulations pour la mesure de paramètres spatiales utilisant un détecteur mulitpixelsThis thesis aims at learning more about nonclassical structured light. Quantum optics and structured light are two topics that are subject to countless scientific examinations. However, they are very rarely combined and the quantum properties of structured light are not as thoroughly studied as they deserve. By structured light, we mean any light fields with complex transverse distributions of intensity, phase or polarization. We want to link the topics of quantum optics and structured light in this thesis. For this purpose, we experimentally generate particular nonclassical structured light fields. In particular, we construct an experimental setup that enables us, in principle, to produce arbitrary amplitude squeezed vector beams, i.e. light beams with a complex transverse structure of the state of polarization. Furthermore, we analyze spatial properties of light beams, and their quantum noise theoretically. We specifically perform theoretical examinations of the quantum noise in the width of a light beam. To show the feasibility of an experimental verification of our theoretical results, we conduct simulations for the measurement of spatial parameters of a beam's cross-section by a multipixel detector
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Lipfert, Tobias. "Ordering effects in quantum optics." Thesis, Lille 1, 2019. http://www.theses.fr/2019LIL1R007/document.
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En optique quantique, la nature quantique de la lumière se manifeste dans des effets d’ordonnement d’opérateurs, inexistants en optique classique. Cette thèse est consacrée à une étude détaillée de ce type d’effets d’ordonnement dus à la dynamique des systèmes physiques. Nous considérons deux systèmes en particulier, 1) la conversion paramétrique descendante dans un milieu χ (2), et 2) un ion dans un piège de Paul entraı̂né par un champ classique; décrit par un modèle de Jaynes-Cummings non linéaire. Les effets d’ordonnement dans ces systèmes dynamiques sont étudiés via le développement et l’approximation de Magnus. Dans le scénario de conversion paramétrique descendante, nous considérons deux cas, (i) une pompe monochromatique (où une solution exacte de la dynamique est connue) et (ii) une pompe spectralement large. Pour la pompe monochromatique, nous écrivons explicitement la décomposition de Bloch-Messiah et obtenons les modes propres et les paramètres de compression. Nous comparons ces résultats exacts avec les approximations de Magnus en incluant certains ou aucun effets d’ordonnement. Nous effectuons une analyse similaire pour la pompe spectralement large lorsque la décomposition de Bloch-Messiah ne peut être évaluée que numériquement. Pour le modèle dynamique de Jaynes-Cummings non linéaire, nous analysons, à nouveau, les effets d’ordonnement via des approximations de Magnus et obtenons la solution exacte, qui n’avait pas été publiée dans la littérature auparavant. Enfin, nous évaluons pour la première fois les limites supérieures exactes (qui dépassent les limites suffisantes) de la convergence du développement de Magnus pour les deux modèles dynamiques à solutions exactesIn quantum optics, the quantum nature of light manifests itself in operator ordering effects, nonexistent in classical optics. This thesis is devoted to a detailed study of such ordering effects that are due to the dynamics of physical systems. We consider two systems in particular, 1) parametric down-conversion in a χ(2) medium, and 2) an ion in a Paul trap driven by a classical field; described by a nonlinear Jaynes-Cummings model. Ordering effects in these dynamical systems are studied via the Magnus expansion and approximation. In the parametric down-conversion scenario we consider two cases, (i) a monochromatic pump (where an exact solution of the dynamics is known), and (ii) a spectrally broad pump. For the monochromatic pump, we write explicitly the Bloch-Messiah decomposition and obtain the squeezing eigenmodes and parameters. We compare these exact results with the Magnus approximations that contain some or no ordering effects. We perform similar analysis for the spectrally broad pump, where the Bloch-Messiah decomposition can only be evaluated numerically. For the dynamics in the nonlinear Jaynes-Cummings model we again analyze ordering effects via Magnus approximations and obtain the exact solution, which has not been published in the literature before. Lastly, we evaluate the exact upper bounds (which exceed sufficient bounds) of convergence of the Magnus expansion for the two models with exact solutions, for the first time
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McDermott, Roger. "A quantum group approach to some exotic states in quantum optics." Thesis, Open University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261140.
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Kaiser, Florian. "Photonic entanglement engineering for quantum information applications and fundamental quantum optics." Nice, 2012. https://tel.archives-ouvertes.fr/tel-00777002.
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Le but de cette thèse est de développer des sources d’intrication photonique pour étudier les réseaux de communication quantique et l’optique quantique fondamentale. Trois sources très performantes sont construites uniquement autour de composants standards de l’optique intégrée et des télécommunications optiques. La première source génère de l’intrication en polarisation via une séparation déterministe des paires de photons dans deux canaux adjacents des télécommunications. Cette source est donc naturellement adaptée à la cryptographie quantique dans les réseaux à multiplexage en longueurs d’ondes. La seconde source génère, pour la première fois, de l’intrication en time-bins croisés, autorisant l'implémentation de crypto-systèmes quantiques à base d’analyseurs passifs uniquement. La troisième source génère, avec une efficacité record, de l’intrication en polarisation via un convertisseur d’observable temps/polarisation. La bande spectrale des photons peut être choisie sur plus de cinq ordres de grandeur (25 MHz - 4 THz), rendant la source compatible avec toute une variété d’applications avancées, telles que la cryptographie, les relais et les mémoires quantiques. Par ailleurs, cette source est utilisée pour revisiter la notion de Bohr sur la complémentarité des photons uniques en employant un interféromètre de Mach-Zehnder dont la lame séparatrice de sortie se trouve dans une superposition quantique d’être à la fois présente et absente. Enfin, pour adapter la longueur d’onde des paires des photons télécoms intriqués vers les longueurs d’ondes d’absorption des mémoires quantiques actuelles, un convertisseur cohérent de longueur d’onde est présenté et discutéThe aim of this thesis is to develop sources of photonic entanglement to study both quantum networking tasks and some of the foundations of quantum physics. To this end, three high-performance sources are developed, each of them taking extensively advantage of standard telecom fibre optics components. The first source generates polarization entanglement via deterministic pair separation in two adjacent telecommunication channels. This source is naturally suitable for quantum cryptography in wavelength multiplexed network structures. The second source generates for the first time a cross time-bin entangled bi-photon state which allows for quantum key distribution tasks using only passive analyzers. The third source generates, with a record efficiency, polarization entanglement using an energy-time to polarization entanglement transcriber. The photon spectral bandwidth can be chosen over more than five orders of magnitude (25 MHz - 4 THz). This permits implementing the source into existing telecom networks, but also in advanced quantum relay and quantum memory applications. Moreover, this source is used to revisit Bohr’s single-photon wave-particle complementarity notion via employing a Mach-Zehnder interferometer with an output quantum beam-splitter in a true superposition of being present and absent. Finally, to adapt the wavelength of the entangled telecom photon pairs to the absorption wavelength of current quantum memories, a coherent wavelength converter is presented and discussed
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McKeever, Jason Terence Taylor Kimble H. Jeff. "Trapped atoms in cavity QED for quantum optics and quantum information /." Diss., Pasadena, Calif. : California Institute of Technology, 2004. http://resolver.caltech.edu/CaltechETD:etd-06032004-163753.
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Michelberger, Patrick Steffen. "Room temperature caesium quantum memory for quantum information applications." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:19c9421d-0276-4c6d-a641-7640d2981da3.
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Quantum memories are key components in photonics-based quantum information processing networks. Their ability to store and retrieve information on demand makes repeat-until-success strategies scalable. Warm alkali-metal vapours are interesting candidates for the implementation of such memories, thanks to their very long storage times as well as their experimental simplicity and versatility. Operation with the Raman memory protocol enables high time-bandwidth products, which denote the number of possible storage trials within the memory lifetime. Since large time-bandwidth products enable multiple synchronisation trials of probabilistically operating quantum gates via memory-based temporal multiplexing, the Raman memory is a promising tool for such tasks. Particularly, the broad spectral bandwidth allows for direct and technologically simple interfacing with other photonic primitives, such as heralded single photon sources. Here, this kind of light-matter interface is implemented using a warm caesium vapour Raman memory. Firstly, we study the storage of polarisation-encoded quantum information, a common standard in quantum information processing. High quality polarisation preservation for bright coherent state input signals can be achieved, when operating the Raman memory in a dual-rail configuration inside a polarisation interferometer. Secondly, heralded single photons are stored in the memory. To this end, the memory is operated on-demand by feed-forward of source heralding events, which constitutes a key technological capability for applications in temporal multiplexing. Prior to storage, single photons are produced in a waveguide-based spontaneous parametric down conversion source, whose bespoke design spectrally tailors the heralded photons to the memory acceptance bandwidth. The faithful retrieval of stored single photons is found to be currently limited by noise in the memory, with a signal-to-noise ratio of approximately 0.3 in the memory output. Nevertheless, a clear influence of the quantum nature of an input photon is observed in the retrieved light by measuring the read-out signal's photon statistics via the g(2)-autocorrelation function. Here, we find a drop in g(2) by more than three standard deviations, from g(2) ~ 1.69 to g(2) ~ 1.59 upon changing the input signal from coherent states to heralded single photons. Finally, the memory noise processes and their scalings with the experimental parameters are examined in detail. Four-wave-mixing noise is determined as the sole important noise source for the Raman memory. These experimental results and their theoretical description point towards practical solutions for noise-free operation.
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Manzoni, Marco Tommaso. "New systems for quantum nonlinear optics." Doctoral thesis, Universitat Politècnica de Catalunya, 2017. http://hdl.handle.net/10803/461495.
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Photons travelling through free space do not interact with each other. This characteristic makes them perfect candidates to carry quantum information over long distances. On the other hand, processing the information they encode requires interaction mechanisms. In recent years, there have been growing efforts to realize strong, controlled interactions between photons by making them interact with individual atoms, which are intrinsically nonlinear objects. This, and the efforts to understand the phenomena that can emerge, have spawned the new field of`"quantum nonlinear optics."
A number of approaches have been pursued to attain near-deterministic atom-photon interactions, including the use of cavities (CQED), of atomic ensembles, and more recently of dielectric nanostructures able to confine light without defocusing, thus enabling the interaction with atoms trapped in the proximity of the structures. While for the CQED case powerful theoretical tools have been developed to treat the interactions of photons, in the case of atomic ensembles, either in free space or coupled to nanophotonic structures, there is a general lack of theoretical methods beyond the linear regime. This relative lack of understanding also implies that there could be rich new physical phenomena that have thus far not been identified. The overall goal of this thesis is to explore these themes in greater detail.
In Chapter 2 of this thesis we develop a new formalism to calculate the properties of quantum light when interfaced with atomic ensembles. The method consists of using a "spin model" that maps a quasi one-dimensional (1D) light propagation problem to the dynamics of an open 1D interacting spin system, where all of the photon correlations are obtained from those of the spins. The spin dynamics can be numerically solved using the toolbox of matrix product states (MPS), thus providing a technique to study strongly interacting photons in the true many-body limit.
In Chapter 3 we investigate the possibility of creating exotic phases of matter using the recently realized photonic crystal waveguide (PCW)-atoms interface. In particular, we examine the consequences that arise from the strong interatomic forces mediated by the exchange of band gap photons, whose strengths also depend strongly on the internal atomic states (¿spins¿). Taking one realistic model, we show that "quantum crystallization" can occur, in which the emergent spatial orders of atoms depend intricately on the spin correlations.
In Chapter 4 we investigate the possibility of implementing second-order nonlinear quantum optical processes with graphene nanostructures, as a more robust alternative to the use of atomic systems. We quantify the second-order nonlinear properties, showing that the tight confinement of surface plasmons (SP) in graphene gives rise to extraordinary interaction strengths at the single-photon level. Finally, we predict that opportunely engineered arrays of graphene nanostructures can provide a second harmonic generation efficiency comparable with that of state-of-the-art nonlinear crystals, with the high Ohmic losses of graphene serving as the fundamental limitation for deterministic processes.
In Chapter 5 we investigate a new paradigm for quantum memories of light based upon ordered atomic arrays. In particular, we show that the strong constructive interference in optical emission can give rise to a significantly enhanced atom-light interface, as compared to a standard, disordered atomic ensemble. In the case of a single, 2D atomic layer, we find the impressive result that a memory realized with 16 atoms can have the same storage efficiency as an atomic ensemble with optical depth larger than 100.Los fotones que viajan por el espacio libre no interactúan entre sí. Esta característica los hace perfectos candidatos para transportar la información cuántica a largas distancias. Por otro lado, el procesamiento de la información que codifican requiere mecanismos de interacción. En los últimos años se han realizado esfuerzos crecientes para realizar interacciones fuertes y controladas entre los fotones y para comprender las leyes subyacentes que describen los fenómenos que pueden surgir, generando así el nuevo campo de la "óptica cuántica no lineal". Mientras que los materiales tridimensionales tienen coeficientes no lineales extremadamente débiles, se pueden obtener interacciones entre los fotones haciéndolos interactuar con átomos individuales, que son objetos intrínsecamente no lineales, teniendo la capacidad de absorber únicamente un solo fotón a la vez. La realización de interacciones determinísticas entre fotones y átomos es uno de los principales retos de la óptica cuántica no lineal. Para eludir las limitaciones debidas a la pequeña sección eficaz óptica de los átomos y el límite de difracción en el espacio libre, se han aplicado diferentes estrategias, entre ellas el uso de cavidades (CQED), de colectividades atómicas y, más recientemente, de nanoestructuras dieléctricas capaces de confinar la luz sin desenfocarse, permitiendo así la interacción con átomos atrapados en la proximidad de esas estructuras. Mientras que para el caso de la CQED se han desarrollado potentes herramientas teóricas para tratar las interacciones de los fotones, en el caso de colectividades atómicas hay una falta general de métodos teóricos más allá del régimen lineal. Esta relativa falta de comprensión también implica que podría haber nuevos fenómenos físicos interesantes que hasta ahora no se han identificado. El objetivo general de esta tesis es explorar estos temas con mayor detalle. En el capítulo 2 de esta tesis desarrollamos un nuevo formalismo para calcular las propiedades de la luz cuántica cuando interactúa con sistemas atómicos. El método consiste en utilizar un"`modelo de espines" que mapea un problema de propagación de luz cuasi unidimensional (1D) a la dinámica de un sistema abierto unidimensional de espines que interactúan entre sí, donde todas las correlaciones de fotones se obtienen a partir de las de los espines. La dinámica de los espines se puede resolver numéricamente utilizando la caja de herramientas de los estados producto de matrices (MPS), proporcionando así una técnica para estudiar los fotones que interactúan fuertemente en el regimen de la física de muchos cuerpos. En el capítulo 3 se investiga la posibilidad de crear fases exóticas de la materia utilizando la interfaz entre guía de ondas de cristales fotónicos (PCW) y átomos recientemente realizada experimentalmente, donde los modos de la banda de frecuencias prohibidas de la PCW se utilizan para mediar las interacciones de largo alcance entre los átomos. Encontramos un rico diagrama de fases de órdenes emergentes. En el capítulo 4 se investiga la posibilidad de implementar procesos ópticos cuánticos no lineales de segundo orden con nano-estructuras de grafeno, como una alternativa más robusta al uso de sistemas atómicos. Cuantificamos las propiedades no lineales de segundo orden, mostrando que el estrecho confinamiento da lugar a extraordinarias fuerzas de interacción a nivel de un solo fotón y predecimos que un diseño apropiado de las nano-estructuras del grafeno permitiría generar el segundo armónico con una eficiencia comparable a la de los cristales no lineales de última generación. En el capítulo 5, investigamos cómo la emisión cooperativa en memorias cuánticas realizadas con reticulos atómicos afecta su eficiencia, encontrando el impresionante resultado de que una memoria realizada con 16 átomos puede tener la misma eficiencia que un gas cuántico atómico de profundidad óptica mayor que 100.
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Berman, D. Ballester. "Quantum optics in tightly confining media." Thesis, Queen's University Belfast, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.546007.
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Stensson, Katarina. "Quantum Optics in 2D Nonlinear Lattices." Thesis, KTH, Tillämpad fysik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-145893.
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Rodgers, Peter A. "Time-dependent pulses in quantum optics." Thesis, Queen's University Belfast, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356924.
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Tarzi, S. "Dissipation and amplification in quantum optics." Thesis, Imperial College London, 1988. http://hdl.handle.net/10044/1/47271.
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Phoenix, Simon James Daniel. "Entropy and disorder in quantum optics." Thesis, Imperial College London, 1990. http://hdl.handle.net/10044/1/46503.
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Light, Philip Stephen. "Photonic microcells for quantum optics applications." Thesis, University of Bath, 2008. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.512327.
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This thesis presents the development of photonic microcells for use as the host for coherent optics phenomena and related applications. A photonic microcell consists of a length of hollow-core photonic crystal fibre (HC-PCF) with a gas-filled core that is spliced to conventional optical fibre at either end to seal the gas within the fibre. Towards the goal of demonstrating and assessing the coherence properties of quantum optical effects in photonic microcells, the fabrication of two types of HC-PCF is presented. The established photonic bandgap HC-PCF offers extremely low transmission loss of ~10 dB/km over kilometre distances. However, the fibre has a limited transmission bandwidth of ~50 THz and exhibits modal coupling unfavourable for many applications. Work is presented on the tailoring of this fibre by control and shaping of the core-surround in order to improve its modal properties. A second type of HC-PCF is based on a large-pitch lattice, whose guidance relies on a new mechanism. This fibre exhibits a much improved bandwidth (>1000 THz) and has a relatively higher but still practical loss of ~1 dB/m. The development of photonic microcells at microbar pressure level and with low optical insertion loss is shown, an important step in the improvement of the technology for coherent optics applications which will take advantage of the extreme gas-laser interaction efficiency achieved in HC-PCF. Finally, quantum optical effects are demonstrated in HC-PCF and photonic microcells loaded with both the molecular gas acetylene and atomic vapour rubidium. The observation of electromagnetically induced transparency (EIT) in acetylene-filled HC-PCF represents the first such observation in a molecular gas, while the use of a photonic microcell allows a comparison of many experimental configurations to explore the coherence properties of coherent optical systems in the core of a HC-PCF. Furthermore, EIT is observed unambiguously in a rubidium loaded HC-PCF for the first time, and the anti-relaxation effects of a polymer coating demonstrated in this configuration.
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Clark, Paul. "Quantum optics of electrons in graphene." Thesis, University of Southampton, 2017. https://eprints.soton.ac.uk/416896/.
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The unique properties of graphene's band structure can lead to negative refraction of charge carriers incident on PN junctions. When coupled with an angular dependent transmission probability this can be utilised to form a novel split path interferometer. Many practical challenges are present and novel methods of fabrication are required to realise such a device. A large mean free path is required in order to achieve ballistic transport; a fundamental requirement of such a lensing device. Graphene on a hexagonal boron nitride (hBN) substrate is used in order to remove as many scattering sites as possible to enable the devices to be modelled using ballistic transport. Bubbles between graphene and boron nitride flakes are found and a method for their removal explained. Equipment was modified to allow the use of the latest graphene flake dry transfer methods, which enable the fabrication of hBN-graphene-hBN sandwich devices with one dimensional edge contacts. Multiple device designs are proposed which would exhibit interesting physics and give evidence for negative refraction in graphene and for the angular transmission probability of Klein tunnelling. The possibility of using He ion carving to produce a very small quantum point contact was explored and a nanoribbon with a width of 8 nm was fabricated and measured.
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Oser, Dorian. "Integrated silicon photonics for quantum optics." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS455.
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La photonique silicium est un domaine prolifique de l’optique intégrée. Elle permet de miniaturiser de nombreuses fonctionnalités optiques, l’émission laser (en considérant les stratégies d’intégration hybride), la modulation électro-optique, le routage, la détection, pour les télécoms, les LIDAR ou la spectroscopie, la métrologie, les capteurs et laboratoires sur puce, toute en produisant à grande échelle avec une grande précision et à bas coût (grâce au technologies CMOS de la microélectronique). L’optique quantique, quant à elle, souffre d’une grande sensibilité aux vibrations et à l’environnement. Les montages optiques nécessitent stabilité, alignement parfait et un grand nombre d’éléments optiques, ce qui limite son développement à grande échelle. Inversement, tous ces aspects sont naturels en photonique intégrée. Le développement de la photonique quantique est ainsi susceptible de permettre l’implémentation à large échelle de systèmes de clés de cryptage pour les télécoms et le calcul quantique. Les prérequis de la photonique quantique sont globalement plus sévères que ceux de la photonique classique. La génération d’états quantiques nécessite notamment un niveau de réjection de la pompe de plus de 100 dB ; le niveau de bruit photonique ambiant sur la puce est également un facteur à soigner particulièrement dans la mesure où les paires de photons générées par les processus quantiques sont par principe de très faible puissance. Dans ce contexte, cette thèse aborde le développement de composants et de circuits pour la photonique quantique silicium. Le but est de générer des états intriqués en énergie-temps et de pouvoir les manipuler sur une puce. Cela va de la conception à l’utilisation des paires de photons, en passant par la fabrication des circuits intégrés optiques. La qualification des propriétés quantiques est aussi explorée afin de cerner les limitations de la plateforme silicium pour le domaine applicatif visé. L’esprit de ce travail est également de proposer des solutions restantes compatibles avec les canaux de télécommunications standard (ITU), de n’utiliser que des composants fibrés standards pour les connexions à réaliser, tout en restant compatibles avec les techniques de fabrication industrielle des grandes fonderies microélectroniques afin de permettre une future production à grand échelle des circuits photoniques quantiquesSilicon photonics is a dynamic research field of integrated optics. It allows to miniaturize numerous optical functionalities such as lasers, electro-optical modulators, routers, detectors, for telecom wavelengths, LIDAR, sensor, metrology or even spectroscopy, all while been able to propose large scale production high precision technologies. On another side, quantum optics suffers from difficulties to scale optical systems, requires extreme stability, perfect alignment, and many bulky optical elements, while solving these issues follows a natural path in integrated photonics. Development of integrated quantum photonics can thus open the door to cheap, powerful, and scalable systems for quantum cryptography, telecoms, and computation. In a significant way, quantum requirements are not the ones of classical circuits with respect to photonic components and circuits. The generation of quantum states indeed requires more than 100dB of pump laser rejection, while being able to manage ultra-low useful optical signals and get rid of on-chip optical noise. In this context, this thesis is dedicated to the study, dimension, realization, and characterization of silicon photonic components and circuits for quantum optics on a chip. The target goal is to generate entangled states in energy-time and manipulate them on chip. The qualification of the quantum properties is also explored to better understand the limitations of the silicon platform in the followed objectives. Another choice of this work is to stay in telecoms wavelength and aligned with the standard channels (ITU grid), to only use off-the-shelf components, all while been CMOS compatible and compliant with standard fabrication process, this to allow the possibility to produce on large scale
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Dhayal, Suman. "Nonlinear and Quantum Optics Near Nanoparticles." Thesis, University of North Texas, 2015. https://digital.library.unt.edu/ark:/67531/metadc822820/.
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We study the behavior of electric fields in and around dielectric and metal nanoparticles, and prepare the ground for their applications to a variety of systems viz. photovoltaics, imaging and detection techniques, and molecular spectroscopy. We exploit the property of nanoparticles being able to focus the radiation field into small regions and study some of the interesting nonlinear, and quantum coherence and interference phenomena near them. The traditional approach to study the nonlinear light-matter interactions involves the use of the slowly varying amplitude approximation (SVAA) as it simplifies the theoretical analysis. However, SVVA cannot be used for systems which are of the order of the wavelength of the light. We use the exact solutions of the Maxwell's equations to obtain the fields created due to metal and dielectric nanoparticles, and study nonlinear and quantum optical phenomena near these nanoparticles. We begin with the theoretical description of the electromagnetic fields created due to the nonlinear wavemixing process, namely, second-order nonlinearity in an nonlinear sphere. The phase-matching condition has been revisited in such particles and we found that it is not satisfied in the sphere. We have suggested a way to obtain optimal conditions for any type and size of material medium. We have also studied the modifications of the electromagnetic fields in a collection of nanoparticles due to strong near field nonlinear interactions using the generalized Mie theory for the case of many particles applicable in photovoltaics (PV). We also consider quantum coherence phenomena such as modification of dark states, stimulated Raman adiabatic passage (STIRAP), optical pumping in $4$-level atoms near nanoparticles by using rotating wave approximation to describe the Hamiltonian of the atomic system. We also considered the behavior of atomic and the averaged atomic polarization in $7$-level atoms near nanoparticles. This could be used as a prototype to study any $n-$level atomic system experimentally in the presence of ensembles of quantum emitters. In the last chapter, we suggested a variant of a pulse-shaping technique applicable in stimulated Raman spectroscopy (SRS) for detection of atoms and molecules in multiscattering media. We used discrete-dipole approximation to obtain the fields created by the nanoparticles.
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Oskay, Windell Haven. "Atom optics experiments in quantum chaos." Access restricted to users with UT Austin EID Full text (PDF) from UMI/Dissertation Abstracts International, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3040634.
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Hinzer, Karin. "Optical properties of gallium arsenide-based self-assembled quantum dots and quantum dot lasers." Thesis, University of Ottawa (Canada), 2002. http://hdl.handle.net/10393/6055.
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Three-dimensional confinement of carriers eliminates the problem of thermal spreading of carriers observed in higher-dimensional systems. Uniform self-assembled quantum dots (QDs) are obtained using the spontaneous islanding of highly strained III-V semiconductors grown with standard epitaxy. Visible stimulated emission has been obtained with red-emitting AlInAs QDs in AlGaAs barriers. Continuous (CW) threshold current densities below 100A/cm2 have been measured at low temperatures and QD material gain larger than 1.7 x 104 cm-1 demonstrate good material quality. Room temperature lasing has also been observed for higher threshold current densities. For longer wavelengths where the thermionic emission problem is less important, InAs/GaAs lasers can operate at room temperature for current densities below ∼100A/cm2 for wavelengths around 950 nm. The zero-dimensional transitions between confined electrons and holes in artificial atoms allow the observation of state-filling at relatively low level of material excitation. Lasing is observed in the upper QD shells for small gain media, and progress towards the QD ground states for longer cavity lengths. Gain may also be increased by including multiple layers of QDs in the active region. To understand the shell structure of AlInAs/AlGaAs QDs, we present results of interband spectroscopy of single Al0.36In0.64As/Al 0.33Ga0.67As self-assembled QDs. The single dot spectroscopy has been carried out at low temperature as a function of the excitation power and magnetic field up to 8 T. The emission spectra as a function of excitation power show two distinct groups of transitions which we associate with the recombination from ground and excited QD levels with a spacing of ∼70 meV. The application of magnetic field allows to identify the exciton emission as well as the emission from the bi-exciton, and charged exciton complexes with binding energies of ∼5 meV. The binding energies compare favorably with results of calculations. Artificial molecules are studied using coupled QD ensembles and single QD spectroscopy. The coupling between the zero-dimensional states is varied by changing the distance between two layers of stacked InAs/GaAs QDs. Energy level splitting larger than 30 meV of the symmetric and anti-symmetric states of the lowest confined shell are measured and are compared to theory.
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Capelle, Thibault. "Electromechanical cooling and parametric amplification of an ultrahigh-Q mechanical oscillator." Thesis, Sorbonne université, 2020. http://www.theses.fr/2020SORUS045.
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Dans cette thèse, nous avons étudié un système mécanique de très haut facteur de qualité couplé à une cavité micro-onde supraconductrice. Nous présenterons une technique originale de caractérisation des pertes des cavités micro-ondes planaires, ainsi qu’une technique de refroidissement par bande latérale résolue utilisée pour refroidir activement cet oscillateur mécanique à l’aide de la cavité micro-onde. Enfin, nous présenterons des optimisations de cette expérience qui ouvrent la voie au refroidissement de l'oscillateur mécanique dans son état quantique fondamental. Un tel système hybride pourrait jouer le rôle de mémoire quantique sur puce, permettant de stocker les états quantiques non-gaussiens générés par des circuits quantiques supraconducteurs dans des vibrations mécaniques avec des temps de cohérence approchant la secondeIn this thesis, we have studied an ultrahigh quality factor mechanical oscillator coupled to a microwave cavity. We will present an original technique to probe the losses of planar microwave cavities, as well as a resolved sideband cooling technique to actively cool this mechanical oscillator using the microwave cavity. Finally, we will present some optimizations of this experiment which open the path towards the ground state cooling of the mechanical oscillator. Such a hybrid quantum system could be used as an on-chip quantum memory, able to store fragile quantum states generated by superconducting quantum circuits for coherence times approaching a second
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Devitt, Simon John. "Quantum information engineering : concepts to quantum technologies /." Connect to thesis, 2007. http://eprints.unimelb.edu.au/archive/00003925.
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Loock, Peter van. "Quantum communication with continuous variables." Thesis, Bangor University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368766.
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