Download or read book Measuring Atomic Properties with an Atom Interferometer written by Tony David Roberts and published by . This book was released on 2002 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) This thesis presents a new technique to "rephase" the interference pattern at large applied fields, and demonstrates a measurement that is free of this limitation. In addition, most of the systematic errors that plagued the previous polarizability measurement are eliminated by the new technique, and an order of magnitude improvement in precision now appears quite feasible. The remaining systematic errors can be eliminated by measuring the ratio of polarizabilities between two different atoms, a comparison whose precision is better by another order of magnitude.
Download or read book Atom Interferometry written by Paul R. Berman and published by Academic Press. This book was released on 1997-01-08 with total page 497 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of atom interferometry has expanded rapidly in recent years, and todays research laboratories are using atom interferometers both as inertial sensors and for precision measurements. Many researchers also use atom interferometry as a means of researching fundamental questions in quantum mechanics. Atom Interferometry contains contributions from theoretical and experimental physicists at the forefront of this rapidly developing field. Editor Paul R. Berman includes an excellent balance of background material and recent experimental results,providing a general overview of atom interferometry and demonstrating the promise that it holds for the future. - Includes contributions from many of the research groups that have pioneered this emerging field - Discusses and demonstrates new aspects of the wave nature of atoms - Explains the many important applications of atom interferometry, from a measurement of the gravitational constant to atom lithography - Examines applications of atom interferometry to fundamentally important quantum mechanics problems
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 Hot Beats and Tune Outs written by Kayleigh Cassella and published by . This book was released on 2018 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ushered forth by advances in time and frequency metrology, atom interferometry remains an indispensable measurement tool in atomic physics due to its precision and versatility. A sequence of four $\pi/2$ beam splitter pulses can create either an interferometer sensitive to the atom's recoil frequency when the momentum imparted by the light reverses direction between pulse pairs or, when constructed from pulses without such reversal, sensitive to the perturbing potential from an external optical field. Here, we demonstrate the first atom interferometer with laser-cooled lithium, advantageous for its low mass and simple atomic structure. We study both a recoil-sensitive Ramsey-Bord\'e interferometer and interferometry sensitive to the dynamic polarizability of the ground state of lithium. Recoil-sensitive Ramsey-Bord\'e interferometry benefits from lithium's high recoil frequency, a consequence of its low mass. At an interrogation time of 10 ms, a Ramsey-Bord\'e lithium interferometer could achieve sensitivities comparable to those realized at much longer times with heavier alkali atoms. However, in contrast with other atoms that are used for atom interferometry, lithium's unresolved excited-state hyperfine structure precludes the the cycling transition necessary for efficient cooling. Without sub-Doppler cooling techniques. As as result, a lithium atomic gas is typically laser cooled to temperatures around 300 $\mu$K, above the Doppler limit, and well above the recoil temperature of 6 $\mu$K. This higher temperature gas expands rapidly during the operation of an atom interferometer, limiting the experimental interrogation time and preventing spatially resolved detection. In this work, a light-pulse lithium matter-wave interferometer is demonstrated in spite of these limitation. Two-photon Raman interferometer pulses coherently couple the atom's spin and momentum and are thus able to spectrally resolve the outputs. These fast pulses drive conjugate interferometers simultaneously which beat with a fast frequency component proportional to the atomic recoil frequency and an envelope modulated by the two-photon detuning of the Raman transition. We detect the summed signal at short experimental times, preventing perturbation of the signal from vibration noise. This demonstration of a sub-recoil measurement with a super-recoil sample opens the door to similar scheme with other particles that are difficult to trap and cool well, like electrons. An interferometer instead composed of $\pi/2$-pulses with a single direction of momentum transfer, can be sensitive to the dynamic polarizability of the atomic ground state. By scanning the frequency of an external driving field, such a measurement can be used to determine the atom's tune-out wavelength. This is the wavelength at which the frequency-dependent polarizability vanishes due to compensating ac-Stark shifts from other atomic states. Lithium's simple atomic structure allows for a precise computation of properties with only {\em ab initio} wave functions and spectroscopic data. A direct interferometric measurement of lithium's red tune-out wavelength at 670.971626(1) nm, is a precise comparison to existing `all-order' atomic theory computations. It also provides another way to experimentally determine the $S-$ to $P-$ transitions matrix elements, for which large correlations and small values complicate computations. Finally, a future measurement of lithium's ultraviolet tune-out wavelength of at 324.192(2) nm would be sensitive to relativistic approximations in the atomic structure description. Atom interferometry simultaneously verifies existing atomic theory with measurements of atomic properties and searches for exotic physics lurking in plain sight. The techniques developed here broaden the applicability of interferometry and increase measurement sensitivity by simplifying cooling, increasing atom number and reducing the cycle time. Overcoming the current experimental limitations on interrogation time would allow for ultra-precise measurements of both the tune-out wavelength and the fine structure constant.
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 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 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 CORE ELECTRONS AND THE VAN DER WAALS POTENTIAL written by Vincent P. A. Lonij and published by . This book was released on 2011 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation describes new measurements of the van der Waals (vdW) potential energy for atoms near a surface. The measurements presented here were accomplished by studying diffraction a beam of atoms transmitted through a nanograting. I will describe how we improved precision by a factor of 10 over previous diffraction measurements by studying how different types of atoms interact with the same surface. As a result of this new precision, we were able to show for the first time the contribution of atomic core electrons to the atom-surface potential, and experimentally test different atomic structure calculation methods. In addition, this dissertation will describe how changing the width of the grating bars to achieve a particular "magic" grating bar width or rotating a grating to a particular "magic" angle allows us to determine both the atom-surface potential strength and the geometry of the grating. This represents an improvement over several recent studies where uncertainties in the nanograting geometry limited precision in the measurements of the vdW potential. For a complementary measurement, also discussed in this dissertation, we collaborated with the Vigué group in Toulouse, France. In this collaboration we used an atom interferometer to measure the phase shift due to transmission through a nanograting. By combining diffraction data from Tucson with interferometry data from Toulouse we improved the precision of interferometry measurements of the atom-surface potential of a single atomic species by almost a factor of 10 over previous interferometric measurements of the vdW potential. These interferometry measurements also serve to measure the shape of the vdW potential and set a limit on non-Newtonian gravitational interactions at 1-2 nm length scales. Finally, this dissertation will discuss how nanogratings with optimized geometry can improve atom interferometers, for example, with blazed gratings. We discuss next generation atom-surface potential measurements and examine new ways of analyzing diffraction data.
Download or read book High Contrast Measurements with a Bose Einstein Condensate Atom Interferometer written by Billy Ian Robertson and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atom interferometry is a next-generation technique of precision measurement that can vastly outperform its optical analogue. These devices utilise the wave nature of atoms to make interferometric measurements of, for example, gravitational and magnetic fields, inertial effects, and the fine-structure constant. The main focus of this thesis is the creation of a general purpose atom interferometer in free space.We create a Bose-Einstein condensate of ~105 87Rb atoms in a crossed-optical dipole trap. The atomic wave function is coherently manipulated using highly tuned pulses comprising off-resonant light that form our atom-optical elements. These atom optics are analogous to the beam splitters and mirrors in an optical interferometer. By controlling the timing and amplitude of the pulses we demonstrate the ability to excite specific momentum states with high efficiency. The tuned atom optics allows for the construction of an atom interferometer in free space. From this we can measure the recoil velocity of an 87Rb atom and calculate the value of the fine structure constant. We also demonstrate the measurement of magnetic field gradients using atom interferometry. A second method of data readout is also demonstrated, known as contrast interferometry.This increases the rate at which information is obtained and decreases the measurement duration from a few hours to a few minutes.Within the vacuum chamber we also have a copper ring which form the basis of an AC coupled ring trap for atoms. The long term goal is to use this as a waveguide for atom interferometry and, whilst not the main focus of this thesis, we present some proof-of-principle type data demonstrating the ring trap. In addition we show the first Kapitza-Dirac splitting of a BEC within the waveguide which forms the first part of a guided atom interferometer.
Download or read book Spin Squeezing and Non linear Atom Interferometry with Bose Einstein Condensates written by Christian Groß and published by Springer Science & Business Media. This book was released on 2012-01-13 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interferometry, the most precise measurement technique known today, exploits the wave-like nature of the atoms or photons in the interferometer. As expected from the laws of quantum mechanics, the granular, particle-like features of the individually independent atoms or photons are responsible for the precision limit, the shot noise limit. However this “classical” bound is not fundamental and it is the aim of quantum metrology to overcome it by employing entanglement among the particles. This work reports on the realization of spin-squeezed states suitable for atom interferometry. Spin squeezing was generated on the basis of motional and spin degrees of freedom, whereby the latter allowed the implementation of a full interferometer with quantum-enhanced precision.
Download or read book Quantum Interferometry Proceedings Of The Adrratico Conferencer written by Francesco De Martini and published by World Scientific. This book was released on 1994-09-09 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains an up-to-date account of the experimental status of one of the fundamental and intriguing topic of contemporary physics, the one concerned with the concepts of Bohr's complementarity, non-locality and EPR non-separability of quantum objects. Different aspects, both conceptual and technical, of the complex fenomenology involving different quantum particles (neutrons, electrons, photons, atoms) are illustrated with a unifying perpective that enlightens the underlying basic processes. The book includes works by H Rauch (Vienna), S Haroche (Paris), D Greenberger (New York), A Tonomura (Tokyo), L Mandel (Rochester), H Walther (Munich), D Pritchard (MIT), R Chiao (Berkeley), J Franson (Baltimore), G Ghirardi (Trieste) and many others.
Download or read book Advances in the Interplay Between Quantum and Gravity Physics written by Peter G. Bergmann and published by Springer Science & Business Media. This book was released on 2002-04-30 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this XVII Course of the International School of Cosmology and Gravitation devoted to "ADVANCES IN THE INTERPLAY BETWEEN QUANTUM AND GRAVITY PHYSICS" we have considered different aspects of the influence of gravity on quantum systems. In order to achieve this aim, in many lectures, seminars and discussions we have strengthened the interplay between gravity and quantum systems starting from the situation in the early universe based on astrophysical observations, up to the earthly based experiments with atom interferometry for probing the structure of space-time. Thus we have had timely lectures on the quantum field and horizon of a black hole including reviews of the problem of black holes thermodynamics and entropy, quantum information, quantum black holes, quantum evaporation and Hawking radiation, recent advances in stockastic gravity. We have also discussed quantum fluctuations in inflationary universe, quantum effects and reheating after inflation, and superplanckian energies in Hawking radiation. In this regard the subject of spinors in purely affine space-time and Dirac matter according to Weyl in the generalized theory of gravitation were developed . The dualism between space-time and matter has been deeply analyzed in order to see why, for general relativity, this is an obstacle for quantization of the theory. Also canonical Gravity and Mach's principle, torsion and curvature as commutator for Quantum Gravity and Dirac Geometry of real space-time were analysed, together with the problem of 5-Dimensional Projective Unified Field theory and Multidimensional Gravity and Cosmology.
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 Atomic Physics 15 Proceedings Of The Fifteenth International Conference On Atomic Physics written by H B Van Linden Van Den Heuvell and published by World Scientific. This book was released on 1997-07-01 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atomic Physics 15 extends the series of books containing the invited papers presented at each International Conference on Atomic Physics (ICAP). The ICAP, held every two years, provides the atomic physics community with an opportunity to review problems of current interest and to consider future directions in the field. This fifteenth meeting also celebrated the centenary of the discovery of the Zeeman effect.
Download or read book From Quantum to Cosmos written by Slava G. Turyshev and published by World Scientific. This book was released on 2009 with total page 764 pages. Available in PDF, EPUB and Kindle. Book excerpt: Space-based laboratory research in fundamental physics is an emerging research discipline that offers great discovery potential and at the same time could drive the development of technological advances which are likely to be important to scientists and technologists in many other different research fields. The articles in this review volume have been contributed by participants of the international workshop ?From Quantum to Cosmos: Fundamental Physics Research in Space? held at the Airlie Center in Warrenton, Virginia, USA, on May 21?24, 2006. This unique volume discusses the advances in our understanding of fundamental physics that are anticipated in the near future, and evaluates the discovery potential of a number of recently proposed space-based gravitational experiments. Specific research areas covered include various tests of general relativity and alternative theories, search of physics beyond the Standard Model, investigations of possible violations of the equivalence principle, search for new hypothetical long- and short-range forces, variations of fundamental constants, tests of Lorentz invariance and attempts at unification of the fundamental interactions. The book also encompasses experiments aimed at the discovery of novel phenomena, including dark matter candidates, and studies of dark energy.
Download or read book 2001 a Relativistic Spacetime Odyssey written by Ignazio Ciufolini and published by World Scientific. This book was released on 2003 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume offers a comprehensive overview of our understanding of gravity at both the experimental and the theoretical level. Critical reviews by experts cover topics ranging from astrophysics (anisotropies in the cosmic microwave background, gamma ray bursts, neutron stars and astroparticles), cosmology, the status of gravitational wave sources and detectors, verification of Newton's law at short distances, the equivalence principle, gravito-magnetism, measurement theory, time machines and the foundations of Einstein's theory, to string theory and loop quantum gravity.
Download or read book Molecular Beams in Physics and Chemistry written by Bretislav Friedrich and published by Springer Nature. This book was released on 2021-06-19 with total page 639 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Open Access book gives a comprehensive account of both the history and current achievements of molecular beam research. In 1919, Otto Stern launched the revolutionary molecular beam technique. This technique made it possible to send atoms and molecules with well-defined momentum through vacuum and to measure with high accuracy the deflections they underwent when acted upon by transversal forces. These measurements revealed unforeseen quantum properties of nuclei, atoms, and molecules that became the basis for our current understanding of quantum matter. This volume shows that many key areas of modern physics and chemistry owe their beginnings to the seminal molecular beam work of Otto Stern and his school. Written by internationally recognized experts, the contributions in this volume will help experienced researchers and incoming graduate students alike to keep abreast of current developments in molecular beam research as well as to appreciate the history and evolution of this powerful method and the knowledge it reveals.
