Download or read book Adiabatic Quantum Computing with Neutral Cesium written by and published by . This book was released on 2013 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adiabatic Quantum Computing with Neutral Atoms written by and published by . This book was released on 2012 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Improving Quantum Computation with Neutral Cesium written by and published by . This book was released on 2014 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neutral atoms harbor great potential for scalable and efficient quantum computation. The AQuA experiment is an attempt to capitalize on that potential and create a quantum computer out of an array of 49 qubits composed of neutral cesium atoms. This thesis covers various theoretical and experimental attempts to improve the capabilities of quantum computation with neutral cesium in general and the AQuA experiment in particular. First we discuss the theory of the 5dsub5/2sub line in cesium and its properties relevant for cooling and readout of qubits. Following this we present our technical and experimental progress in utilizing the 5dsub5/2sub line. After this we shift to discussing how to improve decoherence times of neutral cesium atoms by finding magic trap conditions and in particular we show that a bichromatic trap can be magic in both magnetic and A.C. electric field simultaneously. Finally, we present a novel scheme for using Rydberg blockade and spontaneous emission from a Rydberg state to achieve entanglement of two or more atoms.
Download or read book Neutral Atom Adiabatic Quantum Computing written by and published by . This book was released on 2013 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Approximability of Optimization Problems through Adiabatic Quantum Computation written by William Cruz-Santos and published by Springer Nature. This book was released on 2022-05-31 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: The adiabatic quantum computation (AQC) is based on the adiabatic theorem to approximate solutions of the Schrödinger equation. The design of an AQC algorithm involves the construction of a Hamiltonian that describes the behavior of the quantum system. This Hamiltonian is expressed as a linear interpolation of an initial Hamiltonian whose ground state is easy to compute, and a final Hamiltonian whose ground state corresponds to the solution of a given combinatorial optimization problem. The adiabatic theorem asserts that if the time evolution of a quantum system described by a Hamiltonian is large enough, then the system remains close to its ground state. An AQC algorithm uses the adiabatic theorem to approximate the ground state of the final Hamiltonian that corresponds to the solution of the given optimization problem. In this book, we investigate the computational simulation of AQC algorithms applied to the MAX-SAT problem. A symbolic analysis of the AQC solution is given in order to understand the involved computational complexity of AQC algorithms. This approach can be extended to other combinatorial optimization problems and can be used for the classical simulation of an AQC algorithm where a Hamiltonian problem is constructed. This construction requires the computation of a sparse matrix of dimension 2n × 2n, by means of tensor products, where n is the dimension of the quantum system. Also, a general scheme to design AQC algorithms is proposed, based on a natural correspondence between optimization Boolean variables and quantum bits. Combinatorial graph problems are in correspondence with pseudo-Boolean maps that are reduced in polynomial time to quadratic maps. Finally, the relation among NP-hard problems is investigated, as well as its logical representability, and is applied to the design of AQC algorithms. It is shown that every monadic second-order logic (MSOL) expression has associated pseudo-Boolean maps that can be obtained by expanding the given expression, and also can be reduced to quadratic forms. Table of Contents: Preface / Acknowledgments / Introduction / Approximability of NP-hard Problems / Adiabatic Quantum Computing / Efficient Hamiltonian Construction / AQC for Pseudo-Boolean Optimization / A General Strategy to Solve NP-Hard Problems / Conclusions / Bibliography / Authors' Biographies
Download or read book Adiabatic Quantum Computation and Quantum Annealing written by Catherine C. McGeoch and published by Springer Nature. This book was released on 2022-06-01 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt: Adiabatic quantum computation (AQC) is an alternative to the better-known gate model of quantum computation. The two models are polynomially equivalent, but otherwise quite dissimilar: one property that distinguishes AQC from the gate model is its analog nature. Quantum annealing (QA) describes a type of heuristic search algorithm that can be implemented to run in the ``native instruction set'' of an AQC platform. D-Wave Systems Inc. manufactures {quantum annealing processor chips} that exploit quantum properties to realize QA computations in hardware. The chips form the centerpiece of a novel computing platform designed to solve NP-hard optimization problems. Starting with a 16-qubit prototype announced in 2007, the company has launched and sold increasingly larger models: the 128-qubit D-Wave One system was announced in 2010 and the 512-qubit D-Wave Two system arrived on the scene in 2013. A 1,000-qubit model is expected to be available in 2014. This monograph presents an introductory overview of this unusual and rapidly developing approach to computation. We start with a survey of basic principles of quantum computation and what is known about the AQC model and the QA algorithm paradigm. Next we review the D-Wave technology stack and discuss some challenges to building and using quantum computing systems at a commercial scale. The last chapter reviews some experimental efforts to understand the properties and capabilities of these unusual platforms. The discussion throughout is aimed at an audience of computer scientists with little background in quantum computation or in physics. Table of Contents: Acknowledgments / Introduction / Adiabatic Quantum Computation / Quantum Annealing / The D-Wave Platform / Computational Experience / Bibliography / Author's Biography
Download or read book Adiabatic Quantum Computing with Dressed Rydberg Atoms written by and published by . This book was released on 2011 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Progress Towards Quantum Computing with Neutral Atom Arrays written by Xiaoyu Jiang (Ph.D.) and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis reports progress towards implementing quantum computing applications on a two-dimensional array of neutral atom qubits. While significant progress has taken place in our lab, here we focus on presenting theoretical analysis on various aspects of the project, to help improve the performance of the main experiment. We finished a thorough analysis of the effect of laser noise on 1- and 2-photon Rabi oscillations, with both theoretical analysis and numerical simulations. We developed a theory to directly match a laser's frequency noise power spectral density to its self-heterodyne spectrum measured experimentally. We also predicted the error generated by white noise and spectra with servo-bumps, and our results match well with numerical simulations. A quasi-static theory was also proposed to estimate the error under certain limits, and has demonstrated a good match to numerics. We designed protocols for multi-qubit neutral atom gates. The protocol implements symmetric adiabatic pulses on the k + 1 atoms in the system to implement CkZ gates and CZk gates. The case that we studied assumed equal Rydberg coupling strengths between data qubits for CkZ gates, and 0 coupling between data qubits for CZk gates. We showed that fidelity >0.99 can be achieved for both types of gates, with gate times
Download or read book Adiabatic Processes Noise and Stochastic Algorithms for Quantum Computing and Quantum Simulation written by Guanglei Xu and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rapid developments in experiments provide promising platforms for realising quantum computation and quantum simulation. This, in turn, opens new possibilities for developing useful quantum algorithms and explaining complex many-body physics. The advantages of quantum computation have been demonstrated in a small range of subjects, but the potential applications of quantum algorithms for solving complex classical problems are still under investigation. Deeper understanding of complex many-body systems can lead to realising quantum simulation to study systems which are inaccessible by other means.This thesis studies different topics of quantum computation and quantum simulation.The first one is improving a quantum algorithm in adiabatic quantum computing, which can be used to solve classical problems like combinatorial optimisation problems and simulated annealing. We are able to reach a new bound of time cost for the algorithm which has a potential to achieve a speed up over standard adiabatic quantum computing. The second topic is to understand the amplitude noise in optical lattices in the context of adiabatic state preparation and the thermalisation of the energy introduced to the system. We identify regimes where introducing certain type of noise in experiments would improve the final fidelity of adiabatic state preparation, and demonstrate the robustness of the state preparation to imperfect noise implementations. We also discuss the competition between heating and dephasing effects, the energy introduced by non-adiabaticity and heating, and the thermalisation of the system after an application of amplitude noise on the lattice. The third topic is to design quantum algorithms to solve classical problems of fluid dynamics. We develop a quantum algorithm based around phase estimation that can be tailored to specific fluid dynamics problems and demonstrate a quantum speed up over classical Monte Carlo methods. This generates new bridge between quantum physics and fluid dynamics engineering, can be used to estimate the potential impact of quantum computers and provides feedback on requirements for implementing quantum algorithms on quantum devices.
Download or read book Adiabatic Quantum Computing with QUBO Formulations written by Richard Hua and published by . This book was released on 2016 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: We study two types of problems in this thesis, graph covering problems including the Dominating Set and Edge Cover which are classic combinatorial problems and the Graph Isomorphism Problem with several of its variations. For each of the problems, we provide efficient quadratic unconstrained binary optimization (QUBO) formulations suitable for adiabatic quantum computers, which are viewed as a real-world enhanced model of simulated annealing. The number of qubits (dimension of QUBO matrices) required to solve the graph covering problems are O(n + n lg n) and O(m + n lg n) respectively, where n is the number of vertices and m is the number of edges. We also extend our formulations for the Minimum Vertex- Weighted Dominating Set problem and Minimum Edge-Weighted Edge Cover problem. For the Graph Isomorphism Problem, we provide two QUBO formulation through two approaches both requiring O(n2) variables. We also provide several different formulations for two extensions of the Graph Isomorphism Problems each requiring a different number of variables ranging from O(n1n2) to O((n1 + 1)n2). We also provide some experimental results using a D-Wave 2X quantum computer with 1098 active qubit-coupled processors on the problems studied here for a selection of known common graphs.
Download or read book Exploring Adiabatic Quantum Computing Trajectories Via Optimal Control written by and published by . This book was released on 2013 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adiabatic Quantum Computation and Quantum written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation Adiabatic quantum computation (AQC) is an alternative to the better-known gate model of quantum computation. The two models are polynomially equivalent, but otherwise quite dissimilar: one property that distinguishes AQC from the gate model is its analog nature. Quantum annealing (QA) describes a type of heuristic search algorithm that can be implemented to run in the native instruction set'' of an AQC platform. D-Wave Systems Inc. manufactures {quantum annealing processor chips} that exploit quantum properties to realize QA computations in hardware. The chips form the centerpiece of a novel computing platform designed to solve NP-hard optimization problems. Starting with a 16-qubit prototype announced in 2007, the company has launched and sold increasingly larger models: the 128-qubit D-Wave One system was announced in 2010 and the 512-qubit D-Wave Two system arrived on the scene in 2013. A 1,000-qubit model is expected to be available in 2014. This monograph presents an introductory overview of this unusual and rapidly developing approach to computation. We start with a survey of basic principles of quantum computation and what is known about the AQC model and the QA algorithm paradigm. Next we review the D-Wave technology stack and discuss some challenges to building and using quantum computing systems at a commercial scale. The last chapter reviews some experimental efforts to understand the properties and capabilities of these unusual platforms. The discussion throughout is aimed at an audience of computer scientists with little background in quantum computation or in physics.
Download or read book On Quantum Simulators and Adiabatic Quantum Algorithms written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This Thesis focuses on different aspects of quantum computation theory: adiabatic quantum algorithms, decoherence during the adiabatic evolution and quantum simulators. After an overview on the area of quantum computation and setting up the formal ground for the rest of the Thesis we derive a general error estimate for adiabatic quantum computing. We demonstrate that the first-order correction, which has frequently been used as a condition for adiabatic quantum computation, does not yield a good estimate for the computational error. Therefore, a more general criterion is proposed, which includes higher-order corrections and shows that the computational error can be made exponentially small - which facilitates significantly shorter evolution times than the first-order estimate in certain situations. Based on this criterion and rather general arguments and assumptions, it can be demonstrated that a run-time of order of the inverse minimum energy gap is sufficient and necessary. Furthermore, exploiting the similarity between adiabatic quantum algorithms and quantum phase transitions, we study the impact of decoherence on the sweep through a second-order quantum phase transition for the prototypical example of the Ising chain in a transverse field and compare it to the adiabatic version of Grover's search algorithm. It turns out that (in contrast to first-order transitions) the impact of decoherence caused by a weak coupling to a rather general environment increases with system size (i.e., number of spins/qubits), which might limit the scalability of the system. Finally, we propose the use of electron systems to construct laboratory systems based on present-day technology which reproduce and thereby simulate the quantum dynamics of the Ising model and the O(3) nonlinear sigma model.
Download or read book Adiabatic Quantum Computing from an Eigenvalue Dynamics Point of View written by Richard D. Wilson and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantum computing with molecular magnets written by Repollés Rabinad, Ana María and published by Prensas de la Universidad de Zaragoza. This book was released on 2016-07-12 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: En esta tesis se han estudiado los imanes moleculares (SMM o Single Molecule Magnets en inglés) como potenciales candidatos para formar parte del procesador de un ordenador cuántico. En concreto, moléculas compuestas por uno, dos o tres iones que actúan como qubits. Por otro lado, se ha desarrollado una nueva generación de microsusceptómetros SQUID de 30 µm de diámetro que ha permitido estudiar el comportamiento de muestras de tamaño nanométrico como un primer paso para verificar el comportamiento de estos SMM aislados de su medio cristalino.
Download or read book Quantum Computing written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2019-04-27 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantum mechanics, the subfield of physics that describes the behavior of very small (quantum) particles, provides the basis for a new paradigm of computing. First proposed in the 1980s as a way to improve computational modeling of quantum systems, the field of quantum computing has recently garnered significant attention due to progress in building small-scale devices. However, significant technical advances will be required before a large-scale, practical quantum computer can be achieved. Quantum Computing: Progress and Prospects provides an introduction to the field, including the unique characteristics and constraints of the technology, and assesses the feasibility and implications of creating a functional quantum computer capable of addressing real-world problems. This report considers hardware and software requirements, quantum algorithms, drivers of advances in quantum computing and quantum devices, benchmarks associated with relevant use cases, the time and resources required, and how to assess the probability of success.
Download or read book Optical Trapping And Manipulation Of Neutral Particles Using Lasers A Reprint Volume With Commentaries written by Arthur Ashkin and published by World Scientific. This book was released on 2006-12-29 with total page 941 pages. Available in PDF, EPUB and Kindle. Book excerpt: This important volume contains selected papers and extensive commentaries on laser trapping and manipulation of neutral particles using radiation pressure forces. Such techniques apply to a variety of small particles, such as atoms, molecules, macroscopic dielectric particles, living cells, and organelles within cells. These optical methods have had a revolutionary impact on the fields of atomic and molecular physics, biophysics, and many aspects of nanotechnology.In atomic physics, the trapping and cooling of atoms down to nanokelvins and even picokelvin temperatures are possible. These are the lowest temperatures in the universe. This made possible the first demonstration of Bose-Einstein condensation of atomic and molecular vapors. Some of the applications are high precision atomic clocks, gyroscopes, the measurement of gravity, cryptology, atomic computers, cavity quantum electrodynamics and coherent atom lasers.A major application in biophysics is the study of the mechanical properties of the many types of motor molecules, mechanoenzymes, and other macromolecules responsible for the motion of organelles within cells and the locomotion of entire cells. Unique in vitro and in vivo assays study the driving forces, stepping motion, kinetics, and efficiency of these motors as they move along the cell's cytoskeleton. Positional and temporal resolutions have been achieved, making possible the study of RNA and DNA polymerases, as they undergo their various copying, backtracking, and error correcting functions on a single base pair basis.Many applications in nanotechnology involve particle and cell sorting, particle rotation, microfabrication of simple machines, microfluidics, and other micrometer devices. The number of applications continues to grow at a rapid rate.The author is the discoverer of optical trapping and optical tweezers. With his colleagues, he first demonstrated optical levitation, the trapping of atoms, and tweezer trapping and manipulation of living cells and biological particles.This is the only review volume covering the many fields of optical trapping and manipulation. The intention is to provide a selective guide to the literature and to teach how optical traps really work.
