724 research outputs found
Zero-Point cooling and low heating of trapped 111Cd+ ions
We report on ground state laser cooling of single 111Cd+ ions confined in
radio-frequency (Paul) traps. Heating rates of trapped ion motion are measured
for two different trapping geometries and electrode materials, where no effort
was made to shield the electrodes from the atomic Cd source. The low measured
heating rates suggest that trapped 111Cd+ ions may be well-suited for
experiments involving quantum control of atomic motion, including applications
in quantum information science.Comment: 4 pages, 6 figures, Submitted to PR
Towards a Cloud Native Big Data Platform using MiCADO
In the big data era, creating self-managing scalable platforms for running big data applications is a fundamental
task. Such self-managing and self-healing platforms involve a
proper reaction to hardware (e.g., cluster nodes) and software (e.g., big data tools) failures, besides a dynamic resizing of the allocated resources based on overload and underload situations and scaling policies. The distributed and stateful nature of big data platforms (e.g., Hadoop-based cluster) makes the management of these platforms a challenging task. This paper aims to design and implement a scalable cloud native Hadoop-based big data platform using MiCADO, an open-source, and a highly customisable multi-cloud orchestration and auto-scaling framework for Docker containers, orchestrated by Kubernetes. The proposed MiCADO-based big data platform automates the deployment and enables an automatic horizontal scaling (in and out) of the underlying cloud infrastructure. The empirical evaluation of the MiCADO-based big data platform demonstrates how easy, efficient, and fast it is to deploy and undeploy Hadoop clusters of different sizes. Additionally, it shows how the platform can automatically be scaled based on user-defined policies (such as CPU-based scaling)
Implementation of Grover's Quantum Search Algorithm in a Scalable System
We report the implementation of Grover's quantum search algorithm in the
scalable system of trapped atomic ion quantum bits. Any one of four possible
states of a two-qubit memory is marked, and following a single query of the
search space, the marked element is successfully recovered with an average
probability of 60(2)%. This exceeds the performance of any possible classical
search algorithm, which can only succeed with a maximum average probability of
50%.Comment: 4 pages, 3 figures, updated error discussio
T-junction ion trap array for two-dimensional ion shuttling, storage and manipulation
We demonstrate a two-dimensional 11-zone ion trap array, where individual
laser-cooled atomic ions are stored, separated, shuttled, and swapped. The trap
geometry consists of two linear rf ion trap sections that are joined at a 90
degree angle to form a T-shaped structure. We shuttle a single ion around the
corners of the T-junction and swap the positions of two crystallized ions using
voltage sequences designed to accommodate the nontrivial electrical potential
near the junction. Full two-dimensional control of multiple ions demonstrated
in this system may be crucial for the realization of scalable ion trap quantum
computation and the implementation of quantum networks.Comment: 3 pages, 5 figure
Science Gateways with Embedded Ontology-based E-learning Support
Science gateways are widely utilised in a range of scientific disciplines to provide user-friendly access to complex distributed computing infrastructures. The traditional approach in science gateway development is to concentrate on this simplified resource access and provide scientists with a graphical user interface to conduct their experiments and visualise the results. However, as user communities behind these gateways are growing and opening their doors to less experienced scientists or even to the general public as “citizen scientists”, there is an emerging need to extend these gateways with training and learning support capabilities. This paper describes a novel approach showing how science gateways can be extended with embedded e-learning support using an ontology-based learning environment called Knowledge Repository Exchange and Learning (KREL). The paper also presents a prototype implementation of a science gateway for analysing earthquake data and demonstrates how the KREL can extend this gateway with ontology-based embedded e-learning support
Entanglement of Trapped-Ion Clock States
A M{\o}lmer-S{\o}rensen entangling gate is realized for pairs of trapped
Cd ions using magnetic-field insensitive "clock" states and an
implementation offering reduced sensitivity to optical phase drifts. The gate
is used to generate the complete set of four entangled states, which are
reconstructed and evaluated with quantum-state tomography. An average
target-state fidelity of 0.79 is achieved, limited by available laser power and
technical noise. The tomographic reconstruction of entangled states
demonstrates universal quantum control of two ion-qubits, which through
multiplexing can provide a route to scalable architectures for trapped-ion
quantum computing.Comment: 6 pages, 5 figure
Multiscale Computation with Interpolating Wavelets
Multiresolution analyses based upon interpolets, interpolating scaling
functions introduced by Deslauriers and Dubuc, are particularly well-suited to
physical applications because they allow exact recovery of the multiresolution
representation of a function from its sample values on a finite set of points
in space. We present a detailed study of the application of wavelet concepts to
physical problems expressed in such bases. The manuscript describes algorithms
for the associated transforms which, for properly constructed grids of variable
resolution, compute correctly without having to introduce extra grid points. We
demonstrate that for the application of local homogeneous operators in such
bases, the non-standard multiply of Beylkin, Coifman and Rokhlin also proceeds
exactly for inhomogeneous grids of appropriate form. To obtain less stringent
conditions on the grids, we generalize the non-standard multiply so that
communication may proceed between non-adjacent levels. The manuscript concludes
with timing comparisons against naive algorithms and an illustration of the
scale-independence of the convergence rate of the conjugate gradient solution
of Poisson's equation using a simple preconditioning, suggesting that this
approach leads to an O(n) solution of this equation.Comment: 33 pages, figures available at
http://laisla.mit.edu/muchomas/Papers/nonstand-figs.ps . Updated: (1) figures
file (figs.ps) now appear with the posting on the server; (2) references got
lost in the last submissio
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