Download or read book Quantum State Manipulation and Quantum Chaos in an Optical Lattice written by Jalani Fox Kanem and published by . This book was released on 2007 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of reversing the sinusoidal potential every q kick periods with q = 0, l, 2,3 are examined numerically with the q = 0, 1, 2 cases being verified experimentally. I have found that when considering the energy absorption of the system the q = 1 case is qualitatively and quantitatively the same as the standard kicked rotor, while the q = 2 case is qualitatively the same as the standard kicked rotor with an effective increase in the scaled dimensionless kick strength parameter, k, of k & rarr; k+ p2 .In this thesis I detail the background, implementation and results of two experiments from relatively different fields of study, both of which involve ultra-cold Rubidium atoms trapped in an optical lattice. The first is an analysis of the superpositions of vibrational states of the lattice. This includes a characterization and modelling of the dephasing of the states, an effect inherent to the lattice. It is found that the lattice geometry is a primary factor in the observed dephasing. This geometry results in position-dependent energy eigenstates in the lattice. Modelling this distribution of energies allows the accurate prediction of several experimental observables and provides useful information for future experiments. Several methods of applying pulse echoes to recover the state in the face of this dephasing are demonstrated, characterized and successfully modelled. The second set of experiments centre around using the optical lattice and Rubidium atoms as a delta-kicked rotor system. First I examine quantum resonances in the delta-kicked rotor. These are characterized by a dramatically increased energy absorption rate, in stark contrast to the momentum localization generally observed. These resonances exist when the effective Planck's constant, a parameter that determines how quantum-mechanically the system behaves, has a value of & plank; & d5;=rs & dot;4p, for integers r and s. However only for & plank; & d5;=r & dot;2p are resonances easily observable. Here I report on the first observation of high-order quantum resonances in a non-condensed atomic sample at values of & plank; & d5;=r16 & dot;4p for integers r = 2--6. Quantum numerical simulations suggest that this observation of high-order resonances indicates a much longer spatial coherence than expected from an initially thermal atomic sample.
Download or read book Enhanced Optical and Electric Manipulation of a Quantum Gas of KRb Molecules written by Jacob P. Covey and published by Springer. This book was released on 2018-10-01 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes significant advances in experimental capabilities using ultracold polar molecules. While ultracold polar molecules are an idyllic platform for quantum chemistry and quantum many-body physics, molecular samples prior to this work failed to be quantum degenerate, were plagued by chemical reactions, and lacked any evidence of many-body physics. These limitations were overcome by loading molecules into an optical lattice to control and eliminate collisions and hence chemical reactions. This led to observations of many-body spin dynamics using rotational states as a pseudo-spin, and the realization of quantum magnetism with long-range interactions and strong many-body correlations. Further, a 'quantum synthesis' technique based on atomic insulators allowed the author to increase the filling fraction of the molecules in the lattice to 30%, a substantial advance which corresponds to an entropy-per-molecule entering the quantum degenerate regime and surpasses the so-called percolations threshold where long-range spin propagation is expected. Lastly, this work describes the design, construction, testing, and implementation of a novel apparatus for controlling polar molecules. It provides access to: high-resolution molecular detection and addressing; large, versatile static electric fields; and microwave-frequency electric fields for driving rotational transitions with arbitrary polarization. Further, the yield of molecules in this apparatus has been demonstrated to exceed 10^5, which is a substantial improvement beyond the prior apparatus, and an excellent starting condition for direct evaporative cooling to quantum degeneracy.
Download or read book Quantum State Preparation in an Optical Lattice PHD written by Steven Eugene Hamann and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Controlling the Quantum World written by National Research Council and published by National Academies Press. This book was released on 2007-06-21 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: As part of the Physics 2010 decadal survey project, the Department of Energy and the National Science Foundation requested that the National Research Council assess the opportunities, over roughly the next decade, in atomic, molecular, and optical (AMO) science and technology. In particular, the National Research Council was asked to cover the state of AMO science, emphasizing recent accomplishments and identifying new and compelling scientific questions. Controlling the Quantum World, discusses both the roles and challenges for AMO science in instrumentation; scientific research near absolute zero; development of extremely intense x-ray and laser sources; exploration and control of molecular processes; photonics at the nanoscale level; and development of quantum information technology. This book also offers an assessment of and recommendations about critical issues concerning maintaining U.S. leadership in AMO science and technology.
Download or read book Quantum versus Chaos written by K. Nakamura and published by Springer Science & Business Media. This book was released on 1997-05-31 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation into quantum transport in mesoscopic or nanoscale systems which are classically chaotic, showing the success and failure of quantal, semiclassical, and random matrix theories in dealing with questions emerging from the mesoscopic cosmos. To reconcile quantum with chaos and to restore genuine temporal chaos in quantum systems, a time-discrete variant of quantum dynamics is proposed. Of interest to graduate students and researchers in physics, chemistry, and mathematics. Annotation copyrighted by Book News, Inc., Portland, OR
Download or read book Quantum Chaos written by G. Casati and published by Elsevier. This book was released on 2015-08-11 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of quantum systems which are chaotic in the classical limit (quantum chaos or quantum chaology) is a very new field of research. Not long ago, it was still considered as an esoteric subject, however this attitude changed radically when it was realized that this subject is relevant to many of the more mature branches of physics. This book presents the accumulated knowledge available up until now and at the same time introduces topics which are being intensively studied at present. Their relevance to other fields such as condensed matter, atomic and nuclear physics is also discussed. The lectures have been divided into two rough categories - background and advanced lectures.
Download or read book Creating Novel Quantum States of Ultracold Bosons in Optical Lattices written by Colin Joseph Kennedy and published by . This book was released on 2017 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultracold atoms in optical lattices are among the most developed platforms of interest for building quantum devices suitable for quantum simulation and quantum computation. Ultracold trapped atoms are advantageous because they are fundamentally indistinguishable qubits that can be prepared with high fidelity in well-defined states and read-out with similarly high fidelities. However, an outstanding challenge for ultracold atoms in optical lattices is to engineer interesting interactions and control the effects of heating that couple the system to states that lie outside the Hilbert space we wish to engineer. In this thesis, I describe a series of experiments and theoretical proposals that address several critical issues facing ultracold atoms in optical lattices. First, I describe experiments where the tunneling behavior of atoms in the lattice is modified to make our fundamentally neutral particles behave as though they are charged particles in a magnetic field. We show how engineering this interaction creates intrinsic degeneracy in the single particle spectrum of the many-body system and how to introduce strong interactions in the system with the goal of producing exotic many-body states such as a bosonic fractional quantum Hall states. Then, I discuss how this technique can be easily generalized to include spin and higher spatial dimensions in order to access a rich variety of new physics phenomena. Next, I report on the realization of a spin-1 Heisenberg Hamiltonian which emerges as the low energy effective theory describing spin ordering in the doubly-occupied Mott insulator of two spin components. This integer spin Heisenberg model is qualitatively different from the half-integer spin model because it contains a gapped, spin-insulating ground state for small inter-spin interaction energies which we call the spin Mott. Using a spin-dependent lattice to control the inter-spin interactions, we demonstrate high-fidelity, reversible loading of the spin-Mott phase and develop a probe of local spin correlations in order to demonstrate a spin entropy below 0.2 kB per spin. Progress on adiabatically driving the quantum phase transition from the spin Mott to the xy-ferromagnetic is discussed along with the progress towards the creation of a quantum gas microscope for single atom detection and manipulation..
Download or read book Manipulating Quantum Systems written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2020-09-14 with total page 315 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of atomic, molecular, and optical (AMO) science underpins many technologies and continues to progress at an exciting pace for both scientific discoveries and technological innovations. AMO physics studies the fundamental building blocks of functioning matter to help advance the understanding of the universe. It is a foundational discipline within the physical sciences, relating to atoms and their constituents, to molecules, and to light at the quantum level. AMO physics combines fundamental research with practical application, coupling fundamental scientific discovery to rapidly evolving technological advances, innovation and commercialization. Due to the wide-reaching intellectual, societal, and economical impact of AMO, it is important to review recent advances and future opportunities in AMO physics. Manipulating Quantum Systems: An Assessment of Atomic, Molecular, and Optical Physics in the United States assesses opportunities in AMO science and technology over the coming decade. Key topics in this report include tools made of light; emerging phenomena from few- to many-body systems; the foundations of quantum information science and technologies; quantum dynamics in the time and frequency domains; precision and the nature of the universe, and the broader impact of AMO science.
Download or read book Dissipative Quantum Chaos and Decoherence written by Daniel Braun and published by Springer. This book was released on 2003-07-01 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: This overview of the state of the art of research in an exciting field mainly emphasizes the development of a semiclassical formalism that allows one to incorporate the effect of dissipation and decoherence in a precise, yet tractable way into the quantum mechanics of classically chaotic systems.
Download or read book Quantum State Control and Characterization in an Optical Lattice microform written by Stefan Henrik Myrskog and published by National Library of Canada = Bibliothèque nationale du Canada. This book was released on 2004 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation I present experimental work on the measurement and manipulation of the center-of-mass motion of laser-cooled atoms. The first experiment described demonstrates cooling of an atom cloud by 'delta-kick cooling'. A thermal cloud of atoms in a vacuum expands ballistically, generating correlations between position and momentum. An appropriate momentum kick, proportional to position, results in slowing down all the atoms in the cloud. Through this technique a cloud of atoms can be cooled by greater than a factor of 10, preserving phase-space density, but decreasing the number density of atoms. By using laser-cooled atoms, it is also possible to confine atoms in potentials created by the AC-Stark shift of the atomic energy levels. Using interfering lasers to create the Stark shift, atoms are confined in a sinusoidal potential called an optical lattice. After preparing atoms in the lowest-energy band of the lattice, a spatial displacement can create coherent superpositions of many states of the potential. A combination of time delays and secondary displacements allows the measurement of the Q (Husimi) and W (Wigner) quasi-probability distributions, each of which completely characterizes the motional state of the atoms. Alternatively, a shallow lattice that only support two long-lived states can be used. The two-state system may be characterized with far fewer measurements, and furthermore, can be used as a model system for a qubit, a quantum representation of a single bit of information, useful for quantum computation. We demonstrate reconstruction of the density matrix in the 2-state system. The two-state system has be further used to characterize the physical action of an operation. By preparing a complete set of input density matrices we perform quantum process tomography for the intrinsic decoherence of the lattice, and two operations that correspond to single qubit rotations.
Download or read book Instabilities and Chaos in Quantum Optics written by F. T. Arecchi and published by Springer. This book was released on 1987 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Instabilities and Chaos in Quantum Optics II written by N.B. Abraham and published by Springer. This book was released on 2013-06-13 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains tutorial papers from the lectures and seminars presented at the NATO Advanced Study Institute on "Instabilities and Chaos in Quantum Optics", held at the "Il Ciocco" Conference Center, Castelvecchio Pascoli, Lucca, Italy, June 28-July 7, 1987. The title of the volume is designated Instabilities and Chaos in Quantum Optics II, because of the nearly coincident publication of a collection of articles on research in this field edited by F.T. Arecchi and R.G. Harrison [Instabilities and Chaos in Quantum Optics, (Springer, Berlin, 1987) 1. That volume provides more detailed information about some of these topics. Together they will serve as a comprehensive and tutorial pair of companion volumes. This school was directed by Prof. Massimo Inguscio, of the Department of Physics, University of Naples, Naples, Italy to whom we express our gratitude on behalf of all lecturers and students. The Scientific Advisory Committee consisted of N.B. Abraham of Bryn Mawr College; F.T. Arecchi of the National Institute of Optics in Florence and the University of Florence, and L.A. Lugiato of the Politechnic Institute of Torino. The school continues the long tradition of Europhysics Summer Schools in Quantum Electronics which have provided instruction and training for young researchers and advanced students working in this field for almost twenty years.
Download or read book Chaotic Quantum Ratchets and Filters with Cold Atoms in Optical Lattices written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantum Chaos in Atom Optics written by Michael Brendan d'Arcy and published by . This book was released on 2002 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Robust Time optimal Control for the One dimensional Optical Lattice for Quantum Computation written by Botan Khani and published by . This book was released on 2011 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantum information is a growing field showing exciting possibilities for computational speed-up and communications. For the successful implementation of quantum computers, high-precision control is required to reach fault-tolerant thresholds. Control of quantum systems pertains to the manipulation of states and their evolution. In order to minimize the effects of the environment on the control operations of the qubits, control pulses should be made time-optimal. In addition, control pulses should be made robust to noise in the system, dispersion in energies and coupling elements, and uncertain parameters. In this thesis, we examine a robust time-optimal gradient ascent technique which is used to develop controls of the motional degrees of freedom for an ensemble of neutral atoms in a one-dimensional optical lattice in the high dispersion regime with shallow trapping potentials. As such, the system is analyzed in the delocalized basis. The system is treated as an ensemble of atoms with a range of possible quasimomenta across the first Brillouin zone. This gives the ensemble of Hamiltonians, indexed by the quasimomenta, a distinct spectra in their motional states and highly inhomogeneous control Hamiltonians. Thus, the optical lattice is seen as a model system for robust control. We find optimized control pulses designed using an ensemble modification of gradient-ascent pulse engineering robust to any range of quasimomentum. We show that it is possible to produce rotation controls with fidelities above 90\% for half of the first Brillouin zone with gate times in the order of several free oscillations. This is possible for a spectrum that shows upwards of 75\% dispersion in the energies of the band structure. We also show that NOT controls for qubit rotations on the entire Brillouin zone fidelities above 99\% were possible for 0.6\% dispersion in energies. The gate times were also in the order of several free oscillations. It is shown that these solutions are palindromic in time due to phase differences in some of the energy couplings when comparing one half of the Brillouin zone to another. We explore the limits of discretized sampling of a continuous ensemble for control.
Download or read book Quantum State Manipulation and Measurement written by Jens Clausen and published by . This book was released on 2006 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantum Chaos in Atom Optics written by Sigurd Dyrting and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
