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NIST Authors in Bold

Displaying 1901 - 1925 of 2503

Parahydrogen-enhanced zero-field nuclear magnetic resonance

May 1, 2011
Author(s)
Svenja A. Knappe, T. Theis, P. Ganssle, G Kervem, M Ledbetter, D Budker, A Pines, John E. Kitching
Nuclear magnetic resonance (NMR) is a powerful analytical tool for determination of molecular structure and function, with broad impact in biology, medicine, materials science, and fundamental research. Conventionally, NMR is performed in multiTesla

The Impact of Dispersion on Amplitude and Frequency Noise in a Yb-fiber Laser Comb

May 1, 2011
Author(s)
Lora L. Nugent-Glandorf, Todd Johnson, Yohei Kobayashi, Scott A. Diddams
We describe a Yb-fiber based laser comb, with a focus on the relationship between net cavity dispersion and the amplitude noise and frequency noise on the comb. While tuning the net cavity dispersion from anomalous to normal, we measure the amplitude noise

Microresonator based optical frequency combs

April 29, 2011
Author(s)
Scott A. Diddams, T. J. Klippenberg
Optical frequency combs based on mode-locked laser sources have provided unprecedented measurement capabilities for optical frequencies, enabling new applications in a wide range of topics that include atomic clocks, ultracold gases, molecular

Quamtum coherence between two atoms beyond Q=10 15

April 22, 2011
Author(s)
Chin-Wen Chou, David Hume, Michael J. Thorpe, David J. Wineland, Till P. Rosenband
We place two atoms in quantum superposition states and observe coherent phase evolution for 3.4 × 10 15 cycles. Correlation signals from the two atoms yield information about their relative phase even after the probe radiation has decohered. This technique

Small-sized dichroic atomic vapor laser lock

April 21, 2011
Author(s)
Svenja A. Knappe, Changmin Lee, Geoffrey Z. Iwata, Eric Corsini, James M. Higbie, Micah P. Ledbetter, Dimitry Budkerl
Two, lightweight diode laser frequency stabilization systems designed for experiments in the field are described. Similar to a previous design, magnetic-field lines are contained within a magnetic shield enclosing permanent magnets and Rb cells, so that this

Microfabricated Chip Traps for Ions

April 12, 2011
Author(s)
Jason Amini, Joseph W. Britton, Dietrich G. Leibfried, David J. Wineland
This publication is a review of microfabricated ion traps for a book. We cover the basics of Paul traps, various geometries for realizing the traps, a number of design considerations, and, finally, a review of existing microfabricated traps.

Introduction of a DC Bias into a High-Q Superconducting Microwave Cavity

March 31, 2011
Author(s)
Rimberg J. Alex, Fei Chen, Adam J. Sirois, Raymond Simmonds
We report a technique for applying a dc voltage or current bias to the center conductor of a high-quality factor superconducting microwave cavity without significantly disturbing selected cavity modes. This is accomplished by incorporating dc bias lines

Time Through the Air

March 23, 2011
Author(s)
John P. Lowe
A brief history of the NIST WWVB low frequency (LF) radio station. This includes recent attempts at creating a sister station on the eastern side of the United States and future plans for upgrade of the existing station.

Measurement of equilibrium elemental vapor pressures using x-ray induced fluorescence

March 22, 2011
Author(s)
John J. Curry, Albert Henins, E. G. Estupinan, W. P. Lapatovich, S. D. Shastri
X-ray induced fluorescence is demonstrated as a fast and accurate method for measuring elemental vapor pressures over a wide range of pressures. As such, it may offer a preferable alternative to existing methods such as those based on effusion

Coupled quantized mechanical oscillators

March 10, 2011
Author(s)
Kenton R. Brown, Christian Ospelkaus, Yves Colombe, Andrew C. Wilson, Dietrich G. Leibfried, David J. Wineland
The harmonic oscillator is one of the simplest physical systems but also one of the most fundamental. It is ubiquitous in nature, often serving as an approximation for a more complicated system or as a building block for larger models. Realizations of

The SIM Time Network

March 1, 2011
Author(s)
Michael A. Lombardi, Andrew N. Novick, J. Mauricio Lopez-Romero, Francisco Jimenez, Eduardo de Carlos Lopez, Jean-Simon Boulanger, Raymond Pelletier, Ricardo de Carvalho, Raul Solis, Harold Sanchez, Carlos A. Quevedo, Gregory Pascoe, Daniel Perez, Eduardo Bances, Leonardo Trigo, Victor Masil, Henry Postigo, Anthony Questelles
The Sistema Interamericano de Metrologia (SIM) is a regional metrology organization (RMO) whose members are the national metrology institutes (NMIs) located in the 34 nations of the Organization of American States (OAS). The SIM/OAS region extends

Effect of interactions on edge property measurements in magnetic multilayers

February 25, 2011
Author(s)
Meng Zhu, Robert D. McMichael
This paper reports effects of inter-film interactions on static and dynamic magnetization behavior at film edges in magnetic trilayer stripe arrays under transverse applied fields. The trilayers consist of two magnetic films of Ni80Fe20, 10 nm and 20 nm

Fe xvii X-ray Line Ratios for Accurate Astrophysical Plasma Diagnostics

February 20, 2011
Author(s)
John D. Gillaspy, E. H. Silver, L. Tedesco, Joseph N. Tan, Joshua M. Pomeroy, J M. Laming, G.-X. Chen, T. Lin
New laboratory measurements of the Ne-like Fe xvii x-ray lines in the 15-17 Angstrom range are presented, along with new theoretical predictions. These results establish consistency between independent laboratories and opens the door to trustworthy

Enhanced magnetization drift velocity and current polarization in (CoFe)_{1-x}Ge_{x} alloys

February 17, 2011
Author(s)
Meng Zhu, Brian D. Soe, Robert D. McMichael, Matthew Carey, Stefan Maat, Jeffrey R. Childress
A spin wave Doppler technique is used to measure the drift velocity of the magnetization in current-carrying (CoFe)_{1-x}Ge_{x} alloys. For a current density of 10^11 A/m2, we obtain a large enhancement of drift velocity from 3.1+/-0.2 m/s for CoFe to 8.2+

Spherical Reference Cavities for Ultra-Stable Lasers in Non-Laboratory Environments

February 14, 2011
Author(s)
David R. Leibrandt, Michael J. Thorpe, Mark Notcutt, Robert E. Drullinger, Till P. Rosenband, James C. Bergquist
We present an ultra-stable optical cavity design that is insensitive to both vibrations and orientation. The design is based on a spherical cavity spacer which is held rigidly at two points on a diameter of the sphere. Coupling of the support forces to the

The Infrared Spectra of C2H4+ and C2H3 Trapped in Solid Neon

February 14, 2011
Author(s)
Marilyn E. Jacox, Warren E. Thompson
When a mixture of ethylene in a large excess of neon is codeposited at 4.3 K with a beam of neon atoms that have been excited in a microwave discharge, two groups of product absorptions appear in the infrared spectrum of the deposit. Similar studies using

Characterization of Power-to-Phase Conversion in High-Speed P-I-N Photodiodes

February 1, 2011
Author(s)
Jennifer A. Taylor, Shubahshish Datta, Archita Hati, Craig W. Nelson, Franklyn J. Quinlan, Abhay Joshi, Scott A. Diddams
Fluctuations of the optical power incident on a photodiode can be converted into phase fluctuations of the resulting electronic signal due to nonlinear saturation in the semiconductor. This impacts overall timing stability (phase noise) of microwave

The program LOPT for least-squares optimization of energy levels

February 1, 2011
Author(s)
Alexander Kramida
The article describes a program that solves the least-squares optimization problem for finding the energy levels of a quantum-mechanical system based on a set of measured energy separations or wavelengths of transitions between those energy levels, as well

Use of Phosphor Image Plates for Measuring Intensities in Vacuum Ultraviolet Spectra

January 28, 2011
Author(s)
Gillian Nave, Craig J. Sansonetti, Csilla Szabo, John J. Curry, Darren Smillie
We describe the use of phosphor image plates for recording spectra in the vacuum ultraviolet (VUV) and for determining accurate relative and absolute intensities. We investigated the spatial uniformity, noise level, linearity of the response to VUV light

Quantum information processing and metrology with trapped ions

January 25, 2011
Author(s)
David J. Wineland, Dietrich G. Leibfried
The use of trapped atomic ions in the field of quantum information processing is briefly reviewed. We summarize the basic mechanisms required for logic gates and the use of the gates in demonstrating simple algorithms. We discuss the potential of trapped

Making optical atomic clocks more stable with 10 -16 level laser stabilization

January 23, 2011
Author(s)
Andrew D. Ludlow, Yanyi Jiang, Nathan D. Lemke, Richard W. Fox, Jeffrey A. Sherman, Long-Sheng Ma, Christopher W. Oates
The superb precision of an atomic clock is derived from its stability. Atomic clocks based on optical (rather than microwave) frequencies are attractive because of their potential for high stability, which scales with operational frequency. Nevertheless
Displaying 1901 - 1925 of 2503
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