Dissertations / Theses on the topic 'Atoms'
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Nguyen, Thanh Long. "Study of dipole-dipole interaction between Rydberg atoms : toward quantum simulation with Rydberg atoms." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066695/document.
Full textQuantum simulation offers a highly promising way to understand large correlated quantum systems, and many experimental platforms are now being developed. Rydberg atoms are especially appealing thanks to their strong and short-range dipole-dipole interaction. In our setup, we prepare and manipulate ensembles of Rydberg atoms excited from an ultracold atomic cloud magnetically trapped above a superconducting chip. The dynamics of the Rydberg excitation can be controlled through the laser excitation process. The many-body atomic interaction energy spectrum is then directly measured through microwave spectroscopy. This thesis develops a rigorous Monte Carlo model that provides an insight into the excitation process. Using this model, we discuss a possibility to explore quantum simulations of energy transport in a 1D chain of low angular momentum Rydberg atoms. Furthermore, we propose an innovative platform for quantum simulations. It relies on a groundbreaking approach, based on laser-trapped ensemble of extremely long-lived, strongly interacting circular Rydberg atoms. We present intensive numerical results as well as discuss a wide range of problems that can be addressed with the proposed model
Treutlein, Philipp. "Coherent manipulation of ultracold atoms on atom chips." Diss., kostenfrei, 2008. http://edoc.ub.uni-muenchen.de/9153/.
Full textZuliani, Alexandre. "Vers la manipulation optique d'atomes ultra-froids d'ytterbium excités dans des états de Rydberg." Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS141/document.
Full textThe exacerbated properties of Rydberg atoms have extended the possibilities offered by cold atoms in creating atomic gases in very strong interaction with applications including quantum simulations in many-body physics or in achieving of quantum gates with the dipole blocking phenomenon. The use of cold Rydberg atoms is however currently limited by the fact that it is not possible to continue to apply the experimental techniques of optical manipulation with the atoms to an active electron. The attention of the Rydberg atoms cold community is recently focused on the two active electron atoms offering possibilities, once one of the two electrons excited to a Rydberg state, to provide a second optically active electron that it will be possible to manipulate with laser light.The objective of this thesis is to extend the optical manipulation techniques to atoms with two active electrons excited in Rydberg states, in the case of the ytterbium atom. It has on the one hand the design and assembly of the experimental apparatus for obtaining a source of cold Rydberg ytterbium atoms. Ultimately, this device will allow the optical manipulation of these Rydberg atoms. Furthermore, it presents the development of a numerical model that implements the multichannel quantum defect theory to the theoretical determination of the energy spectrum of ytterbium and its behavior under the influence of external perturbations
Lefèvre, Grégoire. "Développement d’un interféromètre atomique en cavité pour le projet MIGA." Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0063/document.
Full textAfter few decades of development, atom interferometry has become an extremely efficient tool for measuring inertial effects such as accelerations and rotations. Such techniques are now envisioned for a future generation of gravitational wave detectors to push further the limit of the current optical detectors. The Matter-Wave Laser Interferometer Gravitation Antenna (MIGA) instrument will couple atom and optical interferometry to study perturbations of the gravitational field at low-frequencies (Hz and sub-Hz). It will consist of an array of 3 atom interferometers, simultaneously interrogated by the light field resonating inside two 150 m long optical cavities, using a set of high order Bragg pulses π/2 - π - π/2. Gradiometric measurements allows a strong immunity to seismic and newtonian noises which limit optical ground-based detectors such as LIGO and Virgo. A preliminary experiment is being developed at the LP2N laboratory, in Talence (France), where a single atomic cloud is interrogated inside two 80 cm long cavities. In order to interrogate efficiently the 87Rb atoms, a gaussian beam with a radius of several mm resonating inside these cavities is required. This can be achieved by using a marginally stable cavity geometry, composed by two plane mirrors located in the focal planes of a biconvex lens
Bade, Satyanarayana. "Propagation of atoms in a magnetic waveguide on a chip." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066718/document.
Full textIn this thesis we study the propagation of atoms in a magnetic toroidal waveguide, with the aim of developing an inertial sensor. Here, we present different strategies to create the waveguide on an atom chip for a guided Sagnac atom interferometer. We devised three solutions which can be achieved using the same wire configuration. They use the current modulation technique, from a new point of view, which simultaneously tackles the problem of wire corrugation and spin dependent Majorana atom losses. The effect of the multimode propagation of the atoms in the guide is also quantified in this thesis. Using a simple model, we covered the propagation of noninteracting ultracold and thermal gases. We identified the operating conditions to realize a cold atom interferometer with a large dynamic range essential for applications in inertial navigation. Experimentally, the thesis describes the realisation and characterisation of the cold atom source close to a gold coated substrate, as well as the implementation and the characterisation of the atom detection systems
Blockley, Craig Andrew. "Quantum interactions of light and atoms: squeezing of light by atoms and cooling of atoms by light." Thesis, University of Auckland, 1993. http://hdl.handle.net/2292/1966.
Full textRibeiro, Sofia. "Atom-surface interactions with Rydberg atoms : an application to hybrid systems." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/24166.
Full textPalmer, Adam J. "A UV Free Source of Metastable Neon Atoms for Atom Lithography." Thesis, Griffith University, 2011. http://hdl.handle.net/10072/367006.
Full textThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Biomolecular and Physical Sciences
Science, Environment, Engineering and Technology
Full Text
Piotrowicz, Michal J. "Ultracold Rydberg atoms." Thesis, Open University, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.530495.
Full textHolland, Dominic John Martin. "Cracks and atoms /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
Full textLehec, Henri. "Spectroscopie Rydberg et excitation du coeur isolé d'atomes d'ytterbium ultra-froids." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS566/document.
Full textRydberg atoms offer an ideal platform for the study of long-range interacting systems.However, usual techniques for imaging and trapping are unavailable in alkali Rydberg atoms. Our approach rely on the use of a two-optically-active-valence-electrons atom such as ytterbium. Ionic core transitions of this atom offer new perspecives for optical manipulation in the Rydberg state. However,questions remain open, especially on the possibilities of avoiding the autoionization, process which occurs when the atom is doubly excited.In this thesis, we report on the construction of the experiment, from the cooling and trapping of theatoms to the excitation in Rydberg states. Because of the interactions between valence electrons, the spectroscopy of these highly excited states is relatively complicated. An experimental study, coupled to a multi-channel quantum defect analysis (MQDT) has been done on the s,p,d and f Rydberg series. This study produced an improvement on the precision of the spectroscopy of this series by more than two orders of magnitude. We then studied the isolated core excitationon the 6s1/2 -> 6p1/2 transition for Rydberg states of large orbital quantum numbers (l=5-9). This study showed that auto-ionisation is mostly due to the coupling to the continuum of the 5d3/2 core state. In opposition to the barium atom, where auto-ionisation drops rapidly with the orbital quantum number, we have shown that ytterbium is less favourable to that extent. Thanks to this study we will be able to determine which states are good candidates for the optical manipulation
Meister, Matthias [Verfasser]. "Novel concepts for ultra-cold quantum gases in microgravity : equal trap frequencies, atoms trapped by atoms, and the space atom laser / Matthias Meister." Ulm : Universität Ulm, 2019. http://d-nb.info/120207653X/34.
Full textHermann, Avigliano Carla. "Towards deterministic preparation of single Rydberg atoms and applications to quantum information processing." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066351/document.
Full textRydberg atoms and superconducting cavities are remarkable tools for the exploration of basic quantum phenomena and quantum information processing. These giant atoms are blessed with unique properties. They undergo a strong distance-Dependent dipole-Dipole interaction that gives rise to the dipole blockade mechanism: in the Van der Waals regime, this energy shift scales as n11, where n is the principal quantum number. If we shine an excitation laser tuned at the frequency of the isolated atomic transition on an atomic cloud, we expect to excite at most one atom within a blockade volume of ⇠ 8(μm)3. We have set up an experiment to prepare deterministically one Rydberg atom. It uses a small cloud of ground-State Rubidium 87 atoms, magnetically trapped on a superconducting atom chip at 4 K, and laser-Excited to the Rydberg states. The dipole blockade effect is sensitive to the line broadening due to the stray electric fields. Once an atom has been excited to our target state HH 60S1/2↵, we explore the narrow millimeter-Wave transitions between Rydberg states in order to assess these stray fields . With a gold-Coated front surface for the chip, we observe as other groups large field gradients due to slowly deposited Rubidium atoms. We circumvent this problem by coating the chip with a metallic Rubidium layer. This way the gradients are reduced by an order of magnitude. This improvement allows us to observe extremely high coherence times, in the millisecond range, for Rydberg atoms near a superconducting atom-Chip. Theoretically, we present a simple scheme for the fast and efficient generation of quantum superpositions of two coherent fields with different classical amplitudes in a cavity. It relies on the simultaneous interaction of two two-Level atoms with the field. Their final detection with a high probability in the proper state projects the field onto the desired mesoscopic field state superposition (MFSS). We show that the scheme is notably more efficient than those using a single atom. This work is done in the context of cavity QED, where the two-Level systems are circular Rydberg atoms whose lifetime may reach milliseconds, interacting with the field of a superconducting microwave cavity. But this scheme is also highly relevant for the thriving field of circuit-QED. In both contexts, it may lead to interesting experimental studies of decoherence at the quantum-Classical boundary
Albus, Alexander. "Mixtures of Bosonic and Fermionic atoms." Phd thesis, Universität Potsdam, 2003. http://opus.kobv.de/ubp/volltexte/2005/98/.
Full textZuerst wurde der Formalismus der Quantenfeldtheorie auf homogene, atomare Boson-Fermion Gemische erweitert, um grundlegende Größen wie Quasiteilchenspektren, die Grundzustandsenergie und daraus abgeleitete Größen über die Molekularfeldtheorie hinaus zu berechnen.
Unter Zuhilfenahme der dieser Resultate System wurde ein Boson-Fermion Gemisch in einem Fallenpotential im Rahmen der Dichtefunktionaltheorie beschrieben. Daraus konnten die Dichteprofile ermittelt werden und es ließen sich drei Bereiche im Phasendiagramm identifizieren:
(i) ein Bereich eines stabilen Gemisches,
(ii) ein Bereich, in dem die Spezies entmischt sind und
(iii) ein Bereich, in dem das System kollabiert.
Im letzten dieser drei Fällen waren Austausch--Korrelationseffekte signifikant. Weiterhin wurde die Änderung der kritischen Temperatur der Bose-Einstein-Kondensation aufgrund der Boson-Fermion-Wechselwirkung berechnet. Verursacht wird dieser Effekt von Dichtumverteilungen aufgrund der Wechselwirkung.
Dann wurden Boson-Fermion Gemische in optischen Gittern betrachtet. Ein Stabilitätskriterium gegen Phasenentmischung wurde gefunden und es ließen sich Bedingungen für einen supraflüssig zu Mott-isolations Phasenübergang angeben. Diese wurden sowohl mittels einer Molekularfeldrechnung als auch numerisch im Rahmen eines Gutzwilleransatzes gefunden. Es wurden weiterhin neuartige frustrierte Grundzustände im Fall von sehr großen Gitterstärken gefunden.
The theory of atomic Boson-Fermion mixtures in the dilute limit beyond mean-field is considered in this thesis.
Extending the formalism of quantum field theory we derived expressions for the quasi-particle excitation spectra, the ground state energy, and related quantities for a homogenous system to first order in the dilute gas parameter.
In the framework of density functional theory we could carry over the previous results to inhomogeneous systems. We then determined to density distributions for various parameter values and identified three different phase regions:
(i) a stable mixed regime,
(ii) a phase separated regime, and
(iii) a collapsed regime.
We found a significant contribution of exchange-correlation effects in the latter case. Next, we determined the shift of the Bose-Einstein condensation temperature caused by Boson-Fermion interactions in a harmonic trap due to redistribution of the density profiles.
We then considered Boson-Fermion mixtures in optical lattices. We calculated the criterion for stability against phase separation, identified the Mott-insulating and superfluid regimes both, analytically within a mean-field calculation, and numerically by virtue of a Gutzwiller Ansatz. We also found new frustrated ground states in the limit of very strong lattices.
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Anmerkung:
Der Autor ist Träger des durch die Physikalische Gesellschaft zu Berlin vergebenen Carl-Ramsauer-Preises 2004 für die jeweils beste Dissertation der vier Universitäten Freie Universität Berlin, Humboldt-Universität zu Berlin, Technische Universität Berlin und Universität Potsdam.
Hillenbrand, Gerd. "Laser cooling of atoms." Thesis, University of Oxford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.259952.
Full textSteane, A. M. "Laser cooling of atoms." Thesis, University of Oxford, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315817.
Full textGrieves, Brian. "Atoms in strong fields." Thesis, University of Reading, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316144.
Full textEdmunds, P. D. "Trapping ultracold argon atoms." Thesis, University College London (University of London), 2015. http://discovery.ucl.ac.uk/1462806/.
Full textZhao, Yongkai. "Cold atoms and molecules." Thesis, Heriot-Watt University, 2012. http://hdl.handle.net/10399/2688.
Full textConcannon, Edmond Paul. "Hyperpolarizabilities of interacting atoms." Thesis, University of Cambridge, 1996. https://www.repository.cam.ac.uk/handle/1810/283712.
Full textRusjan, Edmond. "Transport of muonic atoms." Diss., Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/81032.
Full textPh. D.
Sala, Simon Johannes. "Ultracold atoms in traps." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät, 2016. http://dx.doi.org/10.18452/17471.
Full textThis thesis aims for a theoretical description of ultracold trapped atoms. The main focus are resonance phenomena due to the coupling of center-of-mass and relative motion, the development of a theoretical approach to treat ultracold few-body systems in versatile trap potentials, and the quantum simulation of attosecond physics with ultracold atoms.
Langlois, Mehdi. "Conception et réalisation d'un gradiomètre de gravité à atomes froids." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066513/document.
Full textThis thesis is about the design and realisation of a new atomic interferometer experiment at SYRTE. It will allow ultra-sensitive measurements of the vertical gradient of gravity. This experiment will work using ultra-cold atoms as a source, prepared on an atom chip. It will use large momentum transfer beam-splitter, obtained by high order Bragg diffraction. The transport of atoms will be provided by moving optical lattices. A first part of the experimental setup was assembled and its operation was validated by producing a dual interferometer. This interferometer is performed on two atomic clouds produced successively from the same source of cold atoms, and interrogated by the same pair of Raman beams. A new method of differential phase extraction has been experimentally demonstrated. It is based on the exploitation of the correlations between the interferometer phase measurements and the estimation of the seismic phase provided by an additional classical sensor
Ammar, Mahdi. "Design and Study of Microwave Potentials for Interferometry with Thermal Atoms On a Chip." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066532/document.
Full textIn this thesis, we report the theoretical study of an atom interferometer using thermal (i.e. non condensed) atoms trapped on a chip, with reduced mean-field effects. To keep an adequate level of coherence, a high level of symmetry between the arms of such an interferometer is required. To achieve this goal, we describe an experimental protocol based on microwave near-fields created by two coplanar waveguides carrying currents oscillating at different frequencies. This method enables the creation of two symmetrical microwave potentials that depend on the atomic internal state, and allows a state-selective symmetrical splitting of the atoms. We mainly consider two symmetrical configurations to separate the atoms either along the longitudinal axis or along the transverse axis of the static magnetic trap. In the case of a transverse splitting of the atoms, we discuss the advantages of using a custom microtrap that has the same field structure as a standard macroscopic Ioffe Pritchard trap, and we propose a practical design for such a microtrap. In the case of an axial splitting of the atoms, we study some physical factors limiting the ultimate performances of this interferometer such as: the dissymmetry of the microwave potentials, the effect of the fluctuations of static and microwave fields and the stability of the interferometer gravitational signal. We derive a simplified one-dimensional harmonic model to describe the interferometer contrast decay. Finally, we consider the possibility of non-adiabatic atomic splitting and recombination without vibrational heating by designing appropriate trajectories of the trapping-potentials based on the theory of dynamical invariants
Hu, Zhen Kimble H. Jeff Kimble H. Jeff. "Quantum optics with cold atoms--nonlinear spectroscopy and road toward single-atom trap /." Diss., Pasadena, Calif. : California Institute of Technology, 1995. http://resolver.caltech.edu/CaltechETD:etd-10112007-092812.
Full textKime, Leila. "Production d'une source d'ions césium monocinétique basée sur des atomes refroidis par laser en vue d'un couplage avec une colonne à faisceaux d'ions focalisés." Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00781962.
Full textFergani, Hadi. "Metal-atom-mediated chemical transformations, the reaction of group 13 metal atoms with arenes." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0017/MQ46480.pdf.
Full textPolo, Gomez Juan. "Tunneling dynamics of ultracold atoms." Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/400375.
Full textThe theory of Quantum Mechanics led to the discovery of many phenomena that were previously hidden by its probabilistic nature. In particular, Quantum Mechanics brought to light the so-called wave-particle duality behavior of extremely small objects. This behavior is typically obtained in isolated systems, therefore experiments where particles do not interact with the environment are basic to study quantum systems and quantum phenomena. Ultracold atoms are systems where atoms are cooled down to temperatures of the order of nanokelvin and, in general, kept in ultrahigh vacuum chambers, such that they can be studied in a highly controlled environment. Within this field, Bose—Einstein condensates (BECs) are a particular appealing state of matter where all the particles of an ultracold bose gas, macroscopically occupy a single quantum state. This behavior makes BECs ideal for studying quantum phenomena at a macroscopic scale. In this thesis, we investigate systems where, a quantum phenomenon that has no analogue in classical mechanics, the quantum tunneling is, or has the potential to be, the mechanism that triggers the dynamics. A tunneling event occurs whenever a massive particle is able to access a classically forbidden region of space without having the necessary kinetic energy to do it. Note that this phenomenon can arise in different scenarios, for instance a particle can tunnel when colliding with a potential barrier or it can simply oscillate between two separated wells separated by a potential barrier. In this context, first, we consider the implementation of a matter-wave bright soliton interferometer whose splitting mechanism is based on tunneling through a finite width barrier. We use bright matter-wave solitons in one dimensional BECs as they present properties, such as their dispersionless behavior, that are ideal for interferometric purposes. As mentioned previously, we are also interested on systems where tunneling occurs between neighboring potentials. For those cases, in order to estimate the tunneling amplitudes that couple the eigenstates of the local traps, the analytical density profiles of the eigenstates are required, especially around the low density regions. In particular, we study the density profiles of harmonically trapped two-component BECs within the miscible phase. The analytical formulation of the density profiles of each component around the low density regions is given by means of universal equations. We then turn our attention to the dynamics of single atoms in tunnel-coupled potentials. First, we study spatial adiabatic passage processes as a robust and efficient technique to transport and load single atoms between cylindrically symmetric concentric potentials. The two processes investigated are based on the matter-wave analogues of the rapid adiabatic passage and of the stimulated Raman adiabatic passage. With these techniques, we are able to transport the atom between two and three rings and to load an ultracold atom from a harmonic potential to a concentric ring. Next, we continue investigating ring potentials, but instead of using concentric rings, we use sided-coupled rings and we demonstrate that in this system, complex tunneling amplitudes appear naturally in the dynamics of single atom angular momentum states. We also propose to use this feature to engineer spatial dark states through quantum interference. Finally, we demonstrate how spatial dark states can be used to create edge-like states in an optical ribbon either for the manifold of ground states of the traps forming the ribbon or for states carrying orbital angular momentum. We show that these states are robust and that can be extended to other geometries. In addition, we suggest to use the winding number associated to the angular momentum as a synthetic dimension opening the possibility to quantum simulate three dimensional systems with two dimensional lattices.
Martini, Ullrich. "Cavity QED with many atoms." Diss., [S.l.] : [s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=963141449.
Full textMcCarthy, Shane. "Electron Correlation Energies in Atoms." Thesis, Fredericton: University of New Brunswick, 2012. http://hdl.handle.net/1882/35886.
Full textSahaguÌn, SaÌnchez Daniel. "Cold atoms trapped near surfaces." Thesis, Imperial College London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.441957.
Full textStephens, Edmund. "Time reversal violation in atoms." Thesis, University of Oxford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334916.
Full textFlynn, Emma L. "Reactive scattering of Rydberg atoms." Thesis, Durham University, 2008. http://etheses.dur.ac.uk/2503/.
Full textScott, Robin George. "Cold atoms in optical lattices." Thesis, University of Nottingham, 2003. http://eprints.nottingham.ac.uk/10010/.
Full textBychkov, Andrey. "Quantum effects in artificial atoms." Thesis, University of Oxford, 2003. http://ora.ox.ac.uk/objects/uuid:93a68cff-9823-47d7-9505-b63806f1bbd4.
Full textRamsbottom, Catherine Anne. "Photoabsorption by atoms and ions." Thesis, Queen's University Belfast, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239229.
Full textCurran, Edwin Paul. "Electron impact ionization of atoms." Thesis, Queen's University Belfast, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328062.
Full textRobinson, David John Robert. "Transitions in medium sized atoms." Thesis, Queen's University Belfast, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359122.
Full textLauder, M. A. "Pulsed multiphoton excitation of atoms." Thesis, Imperial College London, 1985. http://hdl.handle.net/10044/1/37756.
Full textMazurenko, Anton. "Optical imaging of Rydberg atoms." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/78519.
Full textCataloged from PDF version of thesis.
Includes bibliographical references (p. 109-111).
We present an experiment exploring electromagnetically induced transparency (EIT) in Rydberg atoms in order to observe optical nonlinearities at the single photon level. ⁸⁷Rb atoms are trapped and cooled using a magneto-optical trap (MOT) and a far off resonance dipole trap (FORT). Once the system is prepared, a ladder EIT scheme with Rydberg atoms is used to map the photon field onto the ensemble. The powerful dipole interaction between Rydberg atoms allows the system to exhibit many-body quantum mechanical effects. We also describe an imaging method to observe the Rydberg blockade. Last of all, we present a preliminary measurement of EIT in a Rydberg system. In this measurement, the transmission shows sensitivity to the applied photon flux, and exhibits temporal correlations in the photons exiting the EIT medium.
by Anton Mazurenko.
S.B.
Davis, Kendall Bruce. "Evaporative cooling of sodium atoms." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/11384.
Full textHarte, Tiffany. "Ultracold atoms in dressed potentials." Thesis, University of Oxford, 2017. https://ora.ox.ac.uk/objects/uuid:1a4ea098-ec17-414a-8873-95d83ca8ea97.
Full textBirnbaum, Kevin Michael Kimble H. Jeff. "Cavity QED with multilevel atoms /." Diss., Pasadena, Calif. : California Institute of Technology, 2005. http://resolver.caltech.edu/CaltechETD:etd-05272005-103306.
Full textMaruyama, Reina. "Optical trapping of ytterbium atoms /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/9778.
Full textBombardier, Kevin Wilson. "Atoms in quasilocal integral domains." Diss., University of Iowa, 2019. https://ir.uiowa.edu/etd/6709.
Full textMirandés, Rivera Estefania de. "Bloch oscillations of ultracold atoms." Paris 6, 2006. http://www.theses.fr/2006PA066622.
Full textHilico, Adèle. "Capture de forces à atomes piégés dans un réseau optique : caractérisation des performances." Thesis, Paris, Ecole normale supérieure, 2014. http://www.theses.fr/2014ENSU0007/document.
Full textThe thesis presents the set up of the second version of the experiment FORCA-G (CAsimir FORce and Gravitation at short range). The purpose of this experiment is the measurement of short-range interactions between an atom and a massive surface. The measurement is realised thanks to atom interferometers using atoms trapped in a 1D vertical optical lattice. The energy levels of atoms in such a trap are shifted from lattice site to another by the force we aim at measuring. We move the atoms from site to site using counter-propagating Raman transitions. The atoms are moved from Δm lattice sites only if the Raman frequency matches υHFS +∆m.υB where υHFS is the frequency of the hyperfine ground state transition and υB is the Bloch frequency and represents the difference of potential energy between two wells in the case where the atoms are far from the surface. This thesis presents the implementation of a setup properly dedicated to FORCA-G in which the measurement of short-range forces will be possible. It reaches an improved short-term relative sensitivity on the measurement of the Bloch frequency of at 3.9 10-6 at 1s. It contains the studies of the limits in the sensitivity, the accuracy and the contrast losses. It also presents the implementation of a dipolar trap to further cool the atoms and increase their density (crossed dipolar trap with a 1064 broadband laser)
Labuhn, Henning. "Rydberg excitation dynamics and correlations in arbitrary 2D arrays of single atoms." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLO002/document.
Full textIn this thesis, we measure the coherent dynamics and the pair correlations of Rydberg excitations in two-dimensional arrays of single atoms.We use a spatial light modulator to shape the spatial phase of a single optical dipole trap beam before focusing it with a high numerical-aperture aspheric lens. By imprinting an appropriate phase pattern on the trap beam, we can create arbitrarily shaped and easily reconfigurable 2D arrays of high-quality single-atom traps, with trap-spacings of a few micrometers for up to 100 traps. The traps are loaded from a cloud of cold 87Rb atoms, and due to fast light-assisted collisions of atoms inside the traps, at most one atom can be present in each trap at the same time. A sensitive CCD camera allows the real-time, site-resolved imaging of the atomic fluorescence from the traps, enabling us to detect the presence of an atom in each individual trap with almost perfect accuracy.In order to induce strong, tunable interactions between the atoms in the array, we coherently laser-excite them to Rydberg states, which are electronic states with a high principal quantum number.An additional addressing beam allows the individual manipulation of an atom at a selected site in the array.The precise knowledge of both the prepared atom array and the positions of the Rydberg excitations allowed us to measure the collective enhancement of the optical coupling strength in the regime of full Rydberg blockade, where one single excitation is shared symmetrically among all atoms in the array.In the regime where the strong interaction only extends over a few sites, we measured the dynamics and the spatial pair-correlations of Rydberg excitations, in one- and two-dimensional atom arrays. The comparison to a numerical simulation of a quantum Ising model of a spin-1/2 system shows an exceptional agreement for trap geometries where the effect of the anisotropy of the Rydberg-Rydberg interaction is small. The obtained results demonstrate that single Rydberg atoms are a suitable platform for the quantum simulation of spin systems
Antoni-Micollier, Laura. "Interféromètre à atomes froids de 39K et 87Rb pour tester le principe d'équivalence en micropesanteur." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0175/document.
Full textDuring the last two decades, new techniques to cool and manipulate atoms have enabled the development of inertial sensors based on atom interferometry. In this context, the ICE project is based on a compact and transportable dual-species atom interferometer in order to verify the weak equivalence principle (WEP). Thus, we compare the acceleration of two chemical species and verify their equality by measuring the Eötvös parameter at the 10-6 level.This experiment was performed both in the laboratory and in the microgravity environment during parabolic flights onboard the Novespace ZERO-G aircraft. The interferometer is composed of laser-cooled samples of 87Rb and 39K, which exhibit similar transition wavelengths (780 nm and 767 nm) derived from frequency-doubled telecom lasers. Recently, we have performed the first dual species interferometer in microgravity. This enables the first test of the WEP in weightlessness using quantum objects, which represents a major first step toward future mission in space.As part of these experiments, we have implemented a 770 nm laser source, resonant with the D1 transition of 39K, in order to perform a gray molasses cooling. We have also devised a new sequence to prepare atoms in the mF = 0 state with a transfer efficiency above 90%. These techniques improved the contrast of our 39K interferometer by a factor 4, which led to the obtention of a sensitivity on the Eötvös parameter in the laboratory of 5 x 10-8 after 5000 s of integration
Tignone, Edoardo. "Cavity quantum electrodynamics : from photonic crystals to Rydberg atoms." Thesis, Strasbourg, 2016. http://www.theses.fr/2016STRAF008/document.
Full textIn the first chapter of this thesis, we study a quasiperiodic array of dielectric membranes inside a high-finesse Fabry-Pérot cavity. We work within the framework of the transfer matrix formal- ism. We show that, in a transmissive regime, the introduction of a quadratic spatial defect in the membrane positions enhances both the linear and quadratic optomechanical couplings between optical and mechanical degrees of freedom. Finally, we propose a theoretical model to simulate a one-dimensional quasiperiodic photonic crystal. In the second chapter of this thesis, we consider the problem of the transport of an exciton through a one-dimensional chain of two-level systems. We embed the chain of emitters in a transverse optical cavity and we show that, in the strong coupling regime, a ultrafast ballistic transport of the exciton is possible via the polaritonic modes rather than ordinary hopping. Due to the hybrid nature of polaritons, the transport efficiency is particularly robust against disorder and imperfections in the system. In the third chapter of this thesis, we consider an ordered array of cold atoms trapped in an optical lattice inside a hollow-core photonic crystal fiber. We study photon-photon interactions mediated by hard-core repulsion between excitons. We show that, in spite of underlying repulsive interac- tion, photons in the scattering states demonstrate bunching, which can be controlled by tuning the interatomic separation. We interpret this bunching as the result of scattering due to the mismatch of the quantization volumes for excitons and photons, and discuss the dependence of the effect on experimentally relevant parameters. In the fourth chapter of the thesis, we extend the results of the previous chapter to Rydberg atoms