Download or read book Precision Measurement in Atom Interferometry Using Bragg Diffraction written by Brian Vincent Estey and published by . This book was released on 2016 with total page 203 pages. Available in PDF, EPUB and Kindle. Book excerpt: We experimentally and theoretically study Bragg diffraction as a tool for large-momentum transfer beam splitters in atom interferometry. A theoretical framework is developed to quantify the diffraction phase systematic caused by Bragg diffraction and experiments are performed to confirm these predictions using a Ramsey-Bord\'e atom interferometer. We then develop methods to systematically cancel and reduce the diffraction phase systematic by carefully selecting Bragg diffraction parameters and utilizing Bloch oscillations. These techniques are then applied to an ongoing precision measurement of $h/m_\text{Cs}$ for cesium, with the end goal of measuring the fine structure constant $\alpha$. We demonstrate a high contrast simultaneous conjugate Ramsey-Bord\'e interferometer using 5th order Bragg diffraction and 25 common mode Bloch oscillations which achieves $2.5\times 10^6$ radians of phase. We also demonstrate an interferometer with a statistical uncertainty of $\delta \alpha/\alpha=0.25$ ppb after 25 hours of integration time that has diffraction phase systematic error of around 1 ppb. Other sources of systematic uncertainty are also thoroughly explored and determined to better than 0.1 ppb. The techniques and theories developed in this thesis will hopefully help enable future precision measurements based on Bragg diffraction.
Download or read book Modelling Light pulse Atom Interferometry for Precision Measurements written by Jens Jenewein and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atom Interferometry written by G.M. Tino and published by IOS Press. This book was released on 2014-10-16 with total page 807 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since atom interferometers were first realized about 20 years ago, atom interferometry has had many applications in basic and applied science, and has been used to measure gravity acceleration, rotations and fundamental physical quantities with unprecedented precision. Future applications range from tests of general relativity to the development of next-generation inertial navigation systems. This book presents the lectures and notes from the Enrico Fermi school "Atom Interferometry", held in Varenna, Italy, in July 2013. The aim of the school was to cover basic experimental and theoretical aspects and to provide an updated review of current activities in the field as well as main achievements, open issues and future prospects. Topics covered include theoretical background and experimental schemes for atom interferometry; ultracold atoms and atom optics; comparison of atom, light, electron and neutron interferometers and their applications; high precision measurements with atom interferometry and their application to tests of fundamental physics, gravitation, inertial measurements and geophysics; measurement of fundamental constants; interferometry with quantum degenerate gases; matter wave interferometry beyond classical limits; large area interferometers; atom interferometry on chips; and interferometry with molecules. The book will be a valuable source of reference for students, newcomers and experts in the field of atom interferometry.
Download or read book Atom Interferometry with Picokelvin Ensembles in Microgravity written by Merle Cornelius and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atom interferometry enables precision measurements with outstanding sensitivities in a broad field of applications, ranging from fundamental physics to applications in geodesy or navigation. The development of robust and mobile devices paves the way for future satellite missions, e.g. striving for improved spaceborne gravimetry or a precision test of the universality of free fall. The sensitivity of an atom interferometer scales quadratically with the interrogation time. Consequentially, exceptional sensitivities can be reached for interferometry with free evolving ensembles on time scales of several seconds, achievable by operating on a microgravity platform. Such long interrogation times necessarily require ensembles with ultra-low expansion rates, making collimated Bose-Einstein condensates (BEC) the ideal input states. Therefore a method called magnetic lensing is used to narrow the momentum distribution. Together with the very good coherence properties of BECs, this reduces uncertainties in the interferometric measurement and enables high-fidelity beam splitter processes like Bragg diffraction. Within the scope of this thesis, a novel matter-wave lens system is presented to lower the internal kinetic energy of a BEC to the picokelvin regime, which is then used to perform interferometric measurements in microgravity. This is achieved with the QUANTUS-2 apparatus, a high-flux rubidium BEC machine based on atom chip technology, which operates at the drop tower in Bremen. Exploiting the excitation of a quadrupole mode in combination with a magnetic lens attains three-dimensional collimation of the BEC. With this technique, an unprecedented residual kinetic energy of $ sfrac{3}{2}k_B cdot38 ,$pK is achieved, where the ensemble is observed after an interrogation time of 2$ ,$s with a high signal-to-noise ratio. Upgrading the experiment to realize single and double Bragg diffraction enables the first demonstration of a double Bragg-based interferometer in microgravity with a retro-reflection setup. The symmetric splitting achieved with the double Bragg process doubles the enclosed interferometer area and reduces systematic effects compared to single diffraction techniques. A complete characterization is performed to optimize the beam splitting process and verify the feasibility of atom chip setups for interferometric measurements. The potential of magnetically lensed BECs for interferometric measurements is investigated by probing the spatial coherence. To this end, a novel application of shear interferometry is developed to investigate the divergence of the magnetically lensed ensemble in analogy to an optical shear plate. Based on the interferometry pattern, the imperfections of the magnetic lens potential are studied, and the lens strength is optimized. Shear interferometry even enables the spatially resolved determination of the BEC's velocity field based on the interferometry pattern. Consequentially, the internal kinetic energy can be deduced from a single absorption image. Especially compact, ground-based atom interferometers can profit from this characterization method since extended times of flight are not required. This shear interferometry represents a versatile tool to study BEC dynamics independently of the application in matter-wave optics. The first demonstration of interferometry with picokelvin atomic ensembles and the tools developed in this work provide the basis to realize atom interferometry on extended time scales of several seconds. This will ultimately enable future space missions to employ cold atom interferometry at unrivalled levels of precision.
Download or read book The Role of Interactions in Atom Interferometry with Bose Condensed Atoms written by Paul Anthony Altin and published by . This book was released on 2012 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, atom interferometry has become established as an indispensable tool in both fundamental and applied physics. With present state-of-the-art devices based on thermal atoms reaching limits imposed by the momentum spread of the initial atomic wavepacket, it seems natural to ask whether colder sources such as Bose-Einstein condensates may prove beneficial in advancing the precision of interferometric measurements. The thesis at hand aims to inform this question, specifically by examining the role played by atomic interactions in interferometers based on Bose-condensed atoms. Interactions can have both advantageous and deleterious consequences in the context of atom interferometry. They provide a means to control the momentum width of the condensate, and facilitate the generation of nonclassical squeezed states which may enhance the phase sensitivity beyond the shot noise limit. Conversely, the condensate self-interaction causes mean-field shifts, multimode excitations and phase diffusion which can erode both the precision and the accuracy of an interferometric measurement. The question of when and in which systems the detrimental effects of interactions outweigh the advantages of using Bose-Einstein condensates is an important one, and warrants investigation. This thesis presents experimental studies into the role of interactions in both internal- and external-state atom interferometers. As a foundation for these investigations, we describe the design and construction of an apparatus for creating Bose-Einstein condensates of the two stable rubidium isotopes in an optical trap. By sympathetic cooling with a rubidium-87 reservoir, we are able to produce condensates of rubidium-85 in which the interactions may be adjusted by means of a magnetic Feshbach resonance. The tunability afforded by the Feshbach resonance is used to study inelastic losses in ultracold rubidium-85 clouds, as well as the effect of interactions on condensate stability and on the ground state of dual-species mixtures. In particular, we offer new experimental data on the dynamics of collapsing condensates with attractive interactions, over which some controversy has existed since the first experiments more than a decade ago. Good agreement is found between the measured collapse times and a simple mean-field model. Proceeding to interferometry, we present results from Ramsey interferometers operating on the clock transition of rubidium-87 Bose-Einstein condensates. In free-space operation with Raman beamsplitters, we demonstrate projection-noise-limited performance, an important prerequisite for the realisation of squeezing-enhanced sensitivity. Using large condensates of up to 106 atoms and microwave coupling, we study the effect of interactions on the Ramsey fringe contrast. The dominant source of decoherence is found to be spatial dynamics driven by the difference in interparticle interaction strengths, which are analysed using the spin-echo technique and numerical simulations of the Gross-Pitaevskii equation. Finally, we turn our attention to external-state interferometry, implementing a Mach-Zehnder gravimeter using Bragg transitions in a freely falling rubidium-87 condensate. Large-momentum-transfer beamsplitters composed of higher-order Bragg diffraction and Bloch oscillations are used to increase the accumulated phase and thus the sensitivity of the interferometer. The role of interactions in this system is examined, and we canvass methods for achieving further increases in sensitivity. -- provided by Candidate.
Download or read book Atom Interferometry Using Near Resonant Standing Waves of Light written by Peter Digby McDowall and published by . This book was released on 2013 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis details the experimental investigation of a new type of atom interferometer using rubidium-85 atoms in the unexplored near-resonant domain. A cold cloud of atoms, all prepared in the same hyperfine ground state, are subjected to temporally periodic pulses of near-resonant standing waves of light. The standing wave pulses are made to act like an absorption grating where only atoms located around the low intensity region about the nodes remain in the initial ground state, the rest are pumped into a dark hyperfine ground state. The output of the atom interferometer is a measure of the fraction of atoms remaining in the initial ground state after N standing wave pulses for different times between the pulses. An increased survival rate is observed for certain times between pulses due to the occurrence of a coherence echo and the matter wave Talbot effect. This feature allows us to use our atom interferometer to make measurements of the Talbot time which is an important parameter in determinations of the fine structure constant alpha. We provide a theoretical model to describe the relevant physics behind our atom interferometer that compares well with our empirical results. Design and implementation of the apparatus are discussed along with characterisation of parameters such as pulse duration, pulse number, and frequency. Finally we include a demonstration of how, in principle, our atom interferometer could be used to make precision measurements of the Talbot time along with some of the necessary steps to bring it in line with current leading measurements.
Download or read book Clock Atom Interferometry for Precision Measurements in Fundamental Physics written by Thomas Frederick Wilkason and published by . This book was released on 2022 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent technological advances have enabled the development of new precision atomic sensors for tests of fundamental physics. In this thesis, I will introduce the concept of clock atom interferometry, a hybrid of atomic clocks and atom interferometry that is particularly suited for gravitational wave detection and ultralight dark matter searches. I outline the experiment we built to cool and trap strontium atoms for prototyping this concept and demonstrating our initial atom interferometric results. I will then discuss the first realization of large momentum transfer (LMT) clock atom interferometry using single-photon interactions on the strontium 689 nm transition, implementing Mach-Zehnder interferometers and gradiometers with state-of-the-art momentum separation to enhance their sensitivity. Furthermore, using amplitude modulated pulses, I demonstrate Floquet atom optics as a tool to allow symmetric evolution of two states at equal and opposite detuning and allows high pulse efficiencies greater than 99% for all detunings, in particular even when the detuning is on the order of the Rabi frequency. Applying this technique, I extend the visibility of an atom interferometer out to a record momentum transfer in excess of 400 photon momenta. I conclude by demonstrating how this technique can be further advanced to allow for 601 photon momenta of separation, as well as a discussion of the new measurement opportunities made possible with these techniques in the fields of high-precision inertial sensing and fundamental physics detection.
Download or read book Exploring the World with the Laser written by Dieter Meschede and published by Springer. This book was released on 2018-01-02 with total page 799 pages. Available in PDF, EPUB and Kindle. Book excerpt: This edition contains carefully selected contributions by leading scientists in high-resolution laser spectroscopy, quantum optics and laser physics. Emphasis is given to ultrafast laser phenomena, implementations of frequency combs, precision spectroscopy and high resolution metrology. Furthermore, applications of the fundamentals of quantum mechanics are widely covered. This book is dedicated to Nobel prize winner Theodor W. Hänsch on the occasion of his 75th birthday. The contributions are reprinted from a topical collection published in Applied Physics B, 2016. Selected contributions are available open access under a CC BY 4.0 license via link.springer.com. Please see the copyright page for further details.
Download or read book Cpt And Lorentz Symmetry Proceedings Of The Seventh Meeting written by V Alan Kostelecky and published by World Scientific. This book was released on 2017-01-18 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the Proceedings of the Seventh Meeting on CPT and Lorentz Symmetry, held at Indiana University in Bloomington on June 20-24, 2016. The meeting focused on tests of these fundamental symmetries and on related theoretical issues, including scenarios for possible violations.Topics covered at the meeting include experimental and observational searches for CPT and Lorentz violation involving: accelerator and collider experiments; astrophysical birefringence, dispersion, and anisotropy; atomic and molecular spectroscopy; clock-comparison measurements; CMB polarization; decays of atoms, nuclei, and particles; equivalence-principle tests with matter and antimatter; exotic atoms, muonium, positronium; gauge and Higgs particles; gravimetry; gravitational waves; high-energy astrophysical observations; hydrogen and antihydrogen; matter interferometry; neutrino oscillations and propagation, neutrino-antineutrino mixing; oscillations and decays of K, B, D mesons; particle-antiparticle comparisons; post-Newtonian gravity in the solar system and beyond; resonant cavities lasers; second and third-generation particles; sidereal and annual time variations, compass asymmetries; space-based missions; spin-polarized matter; spin precession; tests of short-range gravity; and time-of-flight measurements. Theoretical and phenomenological discussions include: physical effects at the level of the Standard Model, General Relativity, and beyond; origins and mechanisms for violations; classical and quantum field theory, gravitation, particle physics, and strings; mathematical foundations; and Finsler geometry.
Download or read book Ultracold Bosonic and Fermionic Gases written by Kathy Levin and published by Elsevier. This book was released on 2012-11-15 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: The rapidly developing topic of ultracold atoms has many actual and potential applications for condensed-matter science, and the contributions to this book emphasize these connections. Ultracold Bose and Fermi quantum gases are introduced at a level appropriate for first-year graduate students and non-specialists such as more mature general physicists. The reader will find answers to questions like: how are experiments conducted and how are the results interpreted? What are the advantages and limitations of ultracold atoms in studying many-body physics? How do experiments on ultracold atoms facilitate novel scientific opportunities relevant to the condensed-matted community? This volume seeks to be comprehensible rather than comprehensive; it aims at the level of a colloquium, accessible to outside readers, containing only minimal equations and limited references. In large part, it relies on many beautiful experiments from the past fifteen years and their very fruitful interplay with basic theoretical ideas. In this particular context, phenomena most relevant to condensed-matter science have been emphasized. - Introduces ultracold Bose and Fermi quantum gases at a level appropriate for non-specialists - Discusses landmark experiments and their fruitful interplay with basic theoretical ideas - Comprehensible rather than comprehensive, containing only minimal equations
Download or read book A Precision Measurement of the Photon Recoil of an Atom Using Atomic Interferometry written by David Scott Weiss and published by . This book was released on 1993 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Single shot Holographic Readout of an Atom Interferometer written by Andrew Rae MacKellar and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atom interferometry is a precision measurement technique that encodes information in the phase of atomic wavefunctions, using matter-wave interference to project the encoded phase information onto some relatively easy-to-measure property at the interferometer output, like the fractional atomic population in a specific momentum or internal state. Atoms are perturbed by influences to which photons are insensitive, offering atom interferometers excellent sensitivity and access to physics outwith the range of conventional optical interferometers. As such, for probing of fundamental physics such as QED corrections, atoms are an obvious test bed. The primary focus of this thesis is the construction and development of an atom interferometer capable of performing single-shot measurements of the fine-structure constant using a holographic readout technique. This achievement allows the holographic interferometer an increased data acquisition rate on the order of 700-times that [sic] a conventional configuration. As an interfering medium we use a Bose-Einstein condensate containing around ~10[to the power of]5 87Rb atoms. We coherently manipulate the momentum of these atoms with the scattering of photons from an optical lattice with fully controllable intensity. We have developed a numerical toolbox capable of calculating optical-lattice pulse-sequences to generate arbitrary atom-optical operations such as mirrors, and beam-splitters, experimentally demonstrated with an efficiency of 99:97±0:03%. We have used these atom optics to create experimental atom interferometers with various applications, shown here in the cases of a magnetic gradiometer and in measurements of recoil frequency. This latter configuration has been used to perform a measurement of the fine-structure constant with a fractional uncertainty of 6500 ppm in a single shot, with a clear pathway to reduce this uncertainty to 2300 ppm per shot, whilst the increased speed of the holographic interferometer allows a corresponding reduction in uncertainty to 60 ppm within a twelve hour integration period.
Download or read book Atom Optics and Space Physics written by E. Arimondo and published by IOS Press. This book was released on 2009 with total page 519 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The goal of this volume is to discuss the rapidly moving field of atom optics and interferometry with all its intricate aspects ranging from fundamental physics to applications and the theory of relativity. The breathtaking success in manipulating atoms using lasers has encouraged these two so far disjunct communities to move closer together and begin collaborations. After an introduction to atom optics and Bose-Einstein condensation, the theoretical foundations of cold atom interferometers, their use to test gravity, and their implementation in laboratory measurements of the earth rotation and of Newton's gravitational constant are discussed. Several papers discuss the characteristics of gyroscopes and interferometers as sensors for inertial forces, starting from gyroscopes based on light waves and comparing their sensitivity to those based on matter waves. The final topic is the variation of fundamental constants, a subject that during the last years has attracted a lot of --
Download or read book Precision Interferometry with Bose Einstein Condensates written by Alan O. Jamison and published by . This book was released on 2014 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation describes the creation of the first matter-wave interferometer using ytterbium (Yb) atoms. Most of the experiments focus on a contrast interferometer geometry with a Bose-Einstein condensate (BEC) as source. The recoil frequency of the 174-Yb atom is measured with this interferometer. The recoil frequency of an atom is part of a set of precision measurements that together give a value for the fine structure constant. The experimental results of this dissertation lay the groundwork for a future sub part-per-billion (ppb) precision measurement of the Yb recoil frequency. The contrast interferometry technique is extended to substantially longer times scales than those achieved in previous experiments. A measurement at the ~10 parts-per-million level is made. Systematic effects and statistical scaling are studied and found to be compatible with the desired sub-ppb precision for a future measurement. Such a measurement requires a detailed theoretical study of possible systematic shifts to the measured value. A substantial portion of this dissertation consists of this analysis, carried out in sufficient generality as to guide future sub-ppb level measurements. In addition to a large number of possible systematic shifts due to well-understood physics, two more complex effects are identified and studied: Diffraction phases and atom-atom interactions.
Download or read book Precision Measurement with Atom Interferometry Project Supported by the National Basic Research Program of China Grant No 2010CB832805 and the National Natural Science Foundation of China Grant No 11227803 written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Development of atom interferometry and its application in precision measurement are reviewed in this paper. The principle, features and the implementation of atom interferometers are introduced, the recent progress of precision measurement with atom interferometry, including determination of gravitational constant and fine structure constant, measurement of gravity, gravity gradient and rotation, test of weak equivalence principle, proposal of gravitational wave detection, and measurement of quadratic Zeeman shift are reviewed in detail. Determination of gravitational redshift, new definition of kilogram, and measurement of weak force with atom interferometry are also briefly introduced.
Download or read book Atom Optics written by Pierre Meystre and published by Springer Science & Business Media. This book was released on 2001-09-21 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantum mechanics does away with the distinction between particles and waves, and one of the more interesting implications of the wave/particle duality - the discovery that atoms may be manipulated in ways analogous to the manipulation of light with lenses and mirrors - has formed the basis for the relatively new field of atom optics. Pierre Meystre's Atom Optics is the first book entirely devoted to this exciting area of research. Reference links to the leading journals in the field, links to research sites, graphics, and updates can be found online.
Download or read book New Techniques for Precision Atom Interferometry and Applications to Fundamental Tests of Gravity and of Quantum Mechanics written by Tim Kovachy and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Light-pulse atom interferometry--in which quantum mechanical atomic wave packets are split along two paths and later recombined and made to interfere by sequences of optical pulses--is a remarkably sensitive technique for measuring inertial forces, allowing it to be a valuable tool for applications ranging from fundamental tests of gravity to geodesy and inertial navigation. The inertial sensitivity of an atom interferometer is proportional to its enclosed spacetime area--that is, the product of the spatial separation between the two interferometer paths and the interferometer duration. Therefore, new techniques that allow this spacetime area to be increased are essential in order for atom interferometry to reach its full potential. In this thesis, I describe the development of such techniques. We approach the problem of increasing the interferometer spacetime area on two fronts. First, we implement new methods to increase the momentum transferred by the beam splitters of the interferometer. The velocity difference and therefore the spatial separation of the interferometer paths are proportional to this momentum transfer. Conventional atom optics techniques involve beam splitters that transfer two photon momentum recoils (2 hbar k) to the atoms. I will discuss our realization of large momentum transfer (LMT) beam splitters that transfer up to 100 hbar k. Second, we have built a 10 m tall atomic fountain that allows the total interferometer duration to be increased to 2 s. Ultimately, we combined LMT atom optics with long-duration atom interferometry in the 10 m atomic fountain, leading to very large spacetime area atom interferometers. In these very large area atom interferometers, the separation between the two atomic wave packets that respectively travel along the two interferometer paths reaches distances of up to 54 cm. Therefore, in addition to offering greatly increased inertial sensitivity, these interferometers probe the quantum mechanical wavelike nature of matter in a new macroscopic regime. I will discuss the techniques we devised to overcome the many technical challenges associated with such interferometers, which in other apparatus have prevented interference from being maintained for path separations larger than 1 cm. I will also describe initial results from the use of our very large area interferometers to test the equivalence principle with Rb-85 and Rb-87 and our plans for further progress in this direction. Very large area atom interferometry requires high laser power and extremely cold atom sources. We have developed a novel high power, frequency doubled laser source at 780 nm that is suitable for atom optics. Also, we have implemented a sequence of matter wave lenses to prepare and measure atomic ensembles with record-low effective temperatures of 50 pK. In addition to applications in atom interferometry, we expect that such an atom source will be broadly useful for a wide range of experiments.
