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Displaying 37876 - 37900 of 74129

Modeling Quantum Information Systems

August 24, 2004
Author(s)
Paul E. Black, Andrew W. Lane
A simulator for quantum information systems cannot be both general, that is, easily used for every possible system, and efficient. Therefore, some systems will have aspects which can only be simulated by cunning modeling. On the other hand, a simulation

Power dissipation in a vertically integrated chip-scale atomic clock

August 24, 2004
Author(s)
John Kitching, Svenja A. Knappe, Li-Anne Liew, P Schwindt, V Shah, John Moreland, Leo W. Hollberg
The physics package of a vertically-integrated chip-scale atomic clock based on Cs has recently been demonstrated at NIST. This device requires 69 mW of electrical power to maintain the vapor cell 34 K above the temperature of the baseplate. The physics

Improvements in NIST-F1 and a Resulting Accuracy of df/f = 0.61 * 10 -15

August 23, 2004
Author(s)
Thomas P. Heavner, Steven R. Jefferts, Elizabeth A. Donley, Jon H. Shirley, Thomas E. Parker
Over the last several years we have made many improvements to NIST-F1 (a laser-cooled cesium fountain primary frequency standard) resulting in a reduction in the uncertainty by nearly a factor of 2 in the realization of the SI second at NIST. We recently

Microfabricated Atomic Frequency References

August 23, 2004
Author(s)
Svenja A. Knappe, P Schwindt, V Shah, Leo W. Hollberg, John Kitching, Li-Anne Liew, John Moreland
We report on the fabrication of a physics package for a chip-scale atomic clock with a volume of 9.5 mm^3, consuming 75 m W of power. The design is described in detail and is strongly motivated by the goal of wafer-level fabrication and assembly. A

The Cesium Physics Package Design for the PARCS Experiment

August 23, 2004
Author(s)
Eric A. Burt, William Klipstein, Steven R. Jefferts
The Primary Atomic Reference Clock in Space (PARCS) is a collaboration between the National Institute of Standards and Technology (NIST), the Jet Propulsion Laboratory (JPL) and the University of Colorado to build a laser-cooled cesium-beam atomic clock as

Theo1 Confidence Intervals

August 23, 2004
Author(s)
T Tasset, David A. Howe, Donald B. Percival
Theoretical variance #1 (Theo1) has been developed at NIST to improve the estimation of long-term frequency stability. Its square-root (Theo1-dev) has two significant improvements over the Allan deviation XX called ¿Adev" in estimlating long-term frequency

Theo1: Characterization of very long-term frequency stability

August 23, 2004
Author(s)
David A. Howe, T Tasset
Theo1 is the first new species of variance that addresses a particularly difficult measurement problem, namely, obtaining reliable estimation of frequency stability for sample periods that are long compared to the length of a data run. Theo1 has

W-band dual channel PM/AM noise measurement system

August 23, 2004
Author(s)
Archita Hati, Craig Nelson, J Nava, David A. Howe, Fred L. Walls
We discuss the performance of a W-band (92 to 96 GHz) PM and AM noise measurement system. The system uses two nearly identical channels to measure the AM or P M noise added by an amplifier or any passive component. It is principally designed to measure

Transport Coefficients of the Lennard-Jones Model Fluid. I. Viscosity

August 22, 2004
Author(s)
J Meier, Arno D. Laesecke, Stephan Kabelac
In an extensive computer simulation study, the transport coefficients of the Lennard-Jones model were determind with high accuracy from equilibrium molecular-dynamics simulations. In the frame of time correlation function theory, the generalized Einstein

Reversible Proton Transfer Dynamics in Bacteriorhodopsin

August 20, 2004
Author(s)
Y. S. Lee, Morris Krauss
Proton transfer in bacteriorhodopsin from the cytoplasm to the extracellular side is initiated from protonated asp96 in the cytoplasmic region towards the deprotonated Schiff base. This occurs in the transition from the photocycle late M state to the N

Large Area Pt/n-GaN Schottky Photodiodes With Extremely Low Leakage Current

August 19, 2004
Author(s)
A Shahid, Robert E. Vest, D Franz, F Yan, Y Zhao, D B. Mott
Pt/n-type GaN Schottky photodiodes with very large active areas (0.25 cm 2 and 1 cmu2 ) which exhibit extremely low leakage currents at low reverse bias are reported. The Schottky photodiodes were fabricated from n-/n+ epitaxial layers grown by low

Nanotechnology in Integrative Systems: Introduction to Integrative Systems

August 17, 2004
Author(s)
Michael Gaitan
These days it's hard to imagine life without the benefits of integration, computers, and the internet. Even simple tasks such as shopping for food have gone 'high tech' with computerized checkout, laser scanners, digital scales, and electronic transactions

Significant papers from the first 50 years of the Boulder Labs

August 16, 2004
Author(s)
Mary E. DeWeese, Margaret Luebs, Heather McCullough
The Department of Commerce Boulder Labs were dedicated on September 14, 1954, in the shadow of World War II, and the of a bright future. This volume presents a snapshot of our research accomplishments in the half century since then. During this time, the

Lumped-Parameter Thermal Modeling of an IPEM using Thermal Component Models

August 15, 2004
Author(s)
J J. Rodriguez, Allen R. Hefner Jr., David W. Berning, M Velez-Reyes, Madelaine H. Hernandez, Jorge Gonz?lez
A thermal model for the CPES IPEM Gen. II is presented. The selected approach is the simulation of the thermal behavior of an experimental IPEM testbed using the 1D finite difference method. An equivalent electrical network representation of the thermal

Fatigue Sensitivity of Y-TZP to Microscale Sharp-Contact Flaws

August 14, 2004
Author(s)
Yu Zhang, Brian R. Lawn
The strength degrading effects of sharp-contact damage are examined for Y-TZP ceramic plates bonded to a plastic substrate. Microscale contacts are made with Vickers and Berkovich diamond indenters at low loads (0.01 N to 10 N) in the ceramic lower

Conducting atomic force microscopy for Nanoscale tunnel barrier characterization

August 13, 2004
Author(s)
Kristine Lang, Dustin Hite, Raymond Simmonds, Robert McDermott, David P. Pappas, John M. Martinis
Increasing demands on nanometer scale properties of oxide tunnel barriers necessitate a consistent means to assess them at these lengths. Here we use conducting atomic force microscopy (CAFM) to characterize aluminum oxide (AlOx)barriers to be used in
Displaying 37876 - 37900 of 74129