365 research outputs found
Scaling and Suppression of Anomalous Heating in Ion Traps
We measure and characterize anomalous motional heating of an atomic ion confined in the lowest quantum levels of a novel rf ion trap that features moveable electrodes. The scaling of heating with electrode proximity is measured, and when the electrodes are cooled from 300 to 150 K, the heating rate is suppressed by an order of magnitude. This provides direct evidence that anomalous motional heating of trapped ions stems from microscopic noisy potentials on the electrodes that are thermally driven. These observations are relevant to decoherence in quantum information processing schemes based on trapped ions and perhaps other charge-based quantum systems
A Workshop to Incorporate Language Development in Teaching Reading
It is the purpose of this paper to describe a workshop designed to teach elementary school teachers how to incorporate language development activities during reading instruction, particularly with children who have language-based reading difficulties
Planar Ion Trap Geometry for Microfabrication
We describe a novel high aspect ratio radiofrequency linear ion trap geometry
that is amenable to modern microfabrication techniques. The ion trap electrode
structure consists of a pair of stacked conducting cantilevers resulting in
confining fields that take the form of fringe fields from parallel plate
capacitors. The confining potentials are modeled both analytically and
numerically. This ion trap geometry may form the basis for large scale quantum
computers or parallel quadrupole mass spectrometers.
PACS: 39.25.+k, 03.67.Lx, 07.75.+h, 07.10+CmComment: 14 pages, 16 figure
An Informal Reading--Language Test
Professionals working with children who need help in language development and reading have reported a positive relationship between reading performance and the development of language skills (Mattingly, 1972; Goodm3n, reported in Gutknecht and Keenan, 1978; Berger, 1978; Semel and Wiig, 1975; Stark, 1975). Semel and Wiig (1975) report that many reading problems are due to a child I s difficulty or inability to understand the ideas being expressed by complex syntactic structures, and Rupley (1974) states that problems in understanding the vocabulary used in reading texts may contribute to reading problems. The relationship and parallelism between reading and language development becomes more evident when considering some of the the correlates that can have an effect on either or both of them: auditory or visual preceptual problems; motivation. Although such correlates are not synonymous with etiologies for poor developmental reading skills, they are conditions often accompanying an inability to read (Kirk, Kliebhan and Lerner, 1978)
An Integrative Reading-Language Approach
This study sought to determine whether third-grade children identified as poor readers (6-12 mos. delay) were able to improve their reading performances after being provided instruction using an integrated reading-language approach. It was speculated that the basis for some or most reading difficulties were language problems resulting from deficiencies in constructing meaning from a spoken or printed message, difficulty understanding and/or remembering the message proposition(s), and incongruities between a child\u27s knowledge of language and linguistic information presented
Integrating Language Activities into Reading Instruction
This study determines if second grade children, who have been identified as having possible listening comprehension problems and language deficiencies, demonstrate improved reading performance with an integrated reading-language treatment approach. A quasi-experimental design included sixteen children in the experimental group and nineteen subjects in the control group. Six operationally defined language behaviors were studied during eleven weeks of treatment. the data were interpreted to imply that certain aspects of an integrative reading-language approach were effective for reading instruction
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
Bright Source of Cold Ions for Surface-Electrode Traps
We produce large numbers of low-energy ions by photoionization of
laser-cooled atoms inside a surface-electrode-based Paul trap. The
isotope-selective trap loading rate of Yb ions/s exceeds
that attained by photoionization (electron impact ionization) of an atomic beam
by four (six) orders of magnitude. Traps as shallow as 0.13 eV are easily
loaded with this technique. The ions are confined in the same spatial region as
the laser-cooled atoms, which will allow the experimental investigation of
interactions between cold ions and cold atoms or Bose-Einstein condensates.Comment: Paper submitted to PRL for review on 2/1/0
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