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NIST Authors in Bold

Displaying 2026 - 2050 of 2581

Effect of metal/substrate interfaces on radio-frequency loss in superconducting coplanar waveguides

November 8, 2010
Author(s)
David S. Wisbey, Jiansong Gao, Fabio C. da Silva, Jeffrey S. Kline, Michael Vissers, David P. Pappas, Leila R. Vale
Microscopic two-level systems (TLSs) are known to contribute to loss in resonant superconducting microwave circuits. This loss increases at low power and temperatures as the TLSs become unsaturated. We find that the loss is dependent on both the substrate

Nuclear Magnetic Resonance Gyroscopes

November 2, 2010
Author(s)
Elizabeth A. Donley
Nuclear magnetic resonance gyroscopes(NMRGs)detect rotation as shift in the Larmor precession frequency of nuclear spins. A review of the open literature on NMRGs is presented, which includes an introduction to the spectroscopic techniques that enable

A comprehensive analysis of the spectrum of Fe II

October 28, 2010
Author(s)
Gillian Nave
A new analysis of the laboratory spectrum of Fe II is described. The aim is to produce a comprehensive list of Fe II lines, based on high-resolution grating and Fourier transform spectra, covering wavelengths from 900 ̊A to 5.5 μm. Particular attention has

Atomic Spectroscopic Databases at NIST

October 28, 2010
Author(s)
Joseph Reader, Alexander Kramida, Yuri Ralchenko
We present recent work at NIST to develop and maintain databases for spectra, transition probabilities, and energy levels of atoms that are astrophysically important. We also describe our programs to critically compile these data as well as the recently

Towards More Accurate Atomic Oscillator Strengths

October 28, 2010
Author(s)
Wolfgang L. Wiese, Jeffrey R. Fuhr, John M. Bridges
Accurate determinations of atomic oscillator strengths have been a problem for a long time, and discrepancies between various numerical results have been substantial. But in recent years considerable progress has been made, especially for weak lines

SIM time scales

October 27, 2010
Author(s)
Michael A. Lombardi, J. Mauricio Lopez-Romero, Nelida Diaz-Munoz
This paper presents an analysis of the performance of some of the time scales generated in the Sistema Interamericano de Metrologia (SIM) region. We emphasize the generation of the first international time scale in near real time, the SIM Time scale (SIMT)

The evolving optical frequency comb

October 22, 2010
Author(s)
Scott A. Diddams
Much as natural historians search for the first roots of our human race, curiosity drives the laser scientist to pursue the roots of his or her own field. This is especially the case in this year where our community celebrates the 50th anniversary of the

Characterization of a Soluble Anthradithiophene Derivative

October 1, 2010
Author(s)
Brad Conrad, Calvin Chan, Marsha A. Loth, Sean R. Parkin, Xinran Zhang, John E. Anthony, David J. Gundlach
The structural and electrical properties of a new solution processable material, 2,8-diflouro-5,11-tert-butyldimethylsilylethynl anthradithiophene (TBDMS), were measured for single crystal and spun cast thin-film transistors. TBDMS is observed to readily

Revised interpretation of the Na I EUV absorption spectrum

September 27, 2010
Author(s)
Alexander Kramida
Spectral data for neutral sodium were recently compiled by Sansonetti (2008 J. Phys. Chem. Ref. Data 37 1659). In that compilation, some of the energy levels of the 2p53snl configurations were quoted from the studies of the absorption spectrum in the

Relativity and Optical Clocks

September 24, 2010
Author(s)
Chin-Wen Chou, David Hume, Till P. Rosenband, David J. Wineland
Albert Einstein's theory of relativity forced us to alter our concepts of reality. One of the more startling outcomes of the theory is that we have to give up our notions of simultaneity. This is manifest in the so-called twin paradox in which a twin

Toward Spin Squeezing with Trapped Ions

September 23, 2010
Author(s)
John J. Bollinger, Hermann Uys, Michael Biercuk, Joseph W. Britton
Building robust instruments capable of making interferometric measurements with precision beyond the standard quantum limit remains an important goal in many metrology laboratories. We describe here the basic concepts underlying spin squeezing experiments

On-Board Signal Integrity for GPS

September 21, 2010
Author(s)
Marc A. Weiss, Pradipta Shome, Ron Beard
The elements of a space-based integrity approach are to monitor the signals on-board the satellite, such that signal performance can be maintained well within desired integrity limits. These elements include 1) a system for monitoring multiple atomic

The Cooper Pair Transistor

September 17, 2010
Author(s)
Jose A. Aumentado
The Cooper pair transistor (CPT) is a superconducting electrometer that has applications in quantum information as well as fundamental superconductivity studies. Since it operates in a near-dissipationless mode, it has potential as a minimally invasive

Generation of optical coherent-state superpositions by number-resolved photon subtraction from the squeezed vacuum

September 9, 2010
Author(s)
Thomas Gerrits, Scott C. Glancy, Tracy S. Clement, Brice R. Calkins, Adriana E. Lita, Aaron Miller, Aaron J. Miller, Alan L. Migdall, Sae Woo Nam, Richard P. Mirin, Emanuel H. Knill
We have created heralded coherent-state superpositions (CSSs) by subtracting up to three photons from a pulse of squeezed vacuum light. To produce such CSSs at a sufficient rate, we used our high-efficiency photon-number-resolving transition edge sensor to

Sub-micron force detection using optically-cooled levitated microspheres

September 3, 2010
Author(s)
Andrew Geraci, Scott B. Papp, John E. Kitching
We propose an experiment using optically trapped and cooled dielectric microspheres for the detection of short-range forces. The center-of-mass motion of a microsphere trapped in vacuum can experience extremely low dissipation and quality factors of 10 12

Reflectance Factor Measurement Complications Due to Near Infrared Fluorescence

September 1, 2010
Author(s)
Maria E. Nadal, Carl C. Miller, Clarence J. Zarobila
The researchers at the National Institute of Standards and Technology (NIST) have found that the widely used orange and red color tiles unexpectedly exhibit near infrared fluorescence. An analysis of the effect this fluorescence component has on the

The Development of a Unified Time and Frequency Program in the SIM Region

September 1, 2010
Author(s)
Michael A. Lombardi, J. Mauricio Lopez-Romero
The Sistema Interamericano de Metrologia (SIM) is one of five major regional metrology organizations (RMOs) recognized by the Bureau International des Poids et Mesures (BIPM). SIM is composed of the national metrology institutes (NMIs) located in the 34

Temperature dependence of the diffusive conductivity of bilayer graphene

August 24, 2010
Author(s)
Shaffique Adam, Mark D. Stiles
Assuming diffusive carrier transport and employing an effective medium theory, we calculate the temperature dependence of bilayer graphene conductivity due to Fermi-surface broadening as a function of carrier density. We find that the temperature
Displaying 2026 - 2050 of 2581
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