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Search Publications

NIST Authors in Bold

Displaying 2051 - 2075 of 2587

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

yocto-Newton force detection sensitivity using trapped ions

August 22, 2010
Author(s)
Michael J. Biercuk, Joseph W. Britton, Hermann Uys, Aaron Vandevender, John Bollinger
Recent experimental advances have shown that it is possible to detect forces arising from electric fields at a level of aN/ √Hz (atto = 10 -18 through coupling of micro or nanofabricated mechanical resonators to a variety of physical systems including

Advances in Coherent Population Trapping for Atomic Clocks

August 10, 2010
Author(s)
John E. Kitching, Vishal Shah
We review advances in the field of coherent population trapping (CPT) over the last decade with respect to the application of this physical phenomenon to atomic frequency references. We provide an overview of both the basic phenomenon of coherent

A Green Laser Pointer Hazard

August 2, 2010
Author(s)
Jemellie Galang, Alessandro Restelli, Edward W. Hagley, Charles W. Clark
An inexpensive green laser pointer was found to emit 20 mW of infrared radiation during normal use. This is potentially a serious hazard that would not be noticed by most users of such pointers. We find that the problem derives from an unsafe design, and

Quantum electrical standards

August 2, 2010
Author(s)
Neil M. Zimmerman
The ampere and other electrical units defined by international agreement are presently established through challenging experiments. A redefinition of those units based on quantum laws would enable a simpler and more reliable realization.

Tripartite interactions between two phase qubits and a resonant cavity

August 1, 2010
Author(s)
Fabio Altomare, Jae Park, Katarina Cicak, Mika Sillanpaa, Michael S. Allman, Adam J. Sirois, Joshua Strong, Jed D. Whittaker, Raymond Simmonds
The ability to create and manipulate the entanglement of a large number of quantum systems lies at the heart of emerging quantum information technologies. Thus far, multipartite entanglement has been achieved using various forms of quantum bits (qubits)

A NIST Disciplined Oscillator

July 26, 2010
Author(s)
Michael A. Lombardi
The National Institute of Standards and Technology (NIST) now offers a service that provides customers with an oscillator locked to UTC(NIST), the United States national standard for frequency and time. A NIST disciplined oscillator (NISTDO) works by

Challenges in SIM to Create a Coordination Program for Time and Frequency

July 26, 2010
Author(s)
J. Mauricio Lopez-Romero, Michael A. Lombardi
The Sistema Interamericano de Metrologia (SIM), one of the world s five major regional metrology organizations (RMOs) recognized by the Bureau International des Poids et Mesures (BIPM), is comprised of national metrology institutes (NMIs) located in all 34

Generation of optical Schrodinger cat states by number-resolved squeezed photon subtraction

July 23, 2010
Author(s)
Thomas Gerrits, Scott Glancy, Tracy S. Clement, Brice R. Calkins, Adriana Lita, Aaron J. Miller, Alan Migdall, Aaron J. Miller, Sae Woo Nam, Richard Mirin, Emanuel Knill
We have generated and measured an approximation of an optical Schrödinger cat state by photon subtraction from squeezed vacuum. Figure 1 shows the experimental scheme. Photons are probabilistically subtracted from squeezed vacuum and detected with a photon

Ground-based observatory operations optimized and enhanced by direct atmospheric measurements

July 22, 2010
Author(s)
John T. McGraw, Peter C. Zimmer, Azzam Mansour, Dean C. Hines, Anthony B. Hull, Lisa Rossmann, Daniel C. Zirzow, Steven W. Brown, Gerald T. Fraser, Keith R. Lykke, Allan W. Smith, John T. Woodward IV, Christopher W. Stubbs
Earth's atmosphere represents a turbulent, turbid refractive element for every ground-based telescope. We describe the significantly enhanced and optimized operation of observatories supported by the combination of a lidar and spectrophotometer that allows

Hyper-Ramsey spectroscopy of optical clock transitions

July 22, 2010
Author(s)
Christopher W. Oates, V. I. Yudin, A. V. Taichenachev, Zeb Barber, Nathan D. Lemke, Andrew D. Ludlow, U Sterr, Ch. Lisdat, F Riehle
We present nonstandard optical Ramsey schemes that use pulses individually tailored in duration, phase and frequency to cancel spurious frequency shifts related to the excitation itself. In particular, the field shifts and their uncertainties can be

Efficient fiber optic detection of trapped ion flourescence

July 9, 2010
Author(s)
Aaron Vandevender, Yves Colombe, Jason Amini, Dietrich G. Leibfried, David J. Wineland
Integration of fiber optics may play a critical role in the development of quantum information processors based on trapped ions, atoms, and quantum dots. Fibers could help enable a scalable and efficient means of collecting light from and delivering light

Double-Resonance Lineshapes in a Cell with Wall Coating and Buffer Gas

June 28, 2010
Author(s)
Svenja A. Knappe, Hugh Robinson
Microwave double resonances were measured is a wall-coated Rb vapor cell as a function of additional buffer gas pressure. These data were compared to similar measurements in an uncoated cell. It was found that the linewidth in the coated cell displays a

Accurate light-time correction due to a gravitating mass

June 7, 2010
Author(s)
Neil Ashby, Bruno Bertotti
This technical paper of mathematical physics arose as an aftermath of the 2002 Cassini experiment, in which the PPN parameter γ was measured with an accuracy ς γ = 2.3 × 10 -5 and found consistent with the rediction γ=1 of general relativity. The Orbit

High Spectral purity oscillator at 40 GHz: Design using air-dielectric Cavity

June 2, 2010
Author(s)
Archita Hati, Craig W. Nelson, Billy F. Riddle, David A. Howe
We describe the design of a low-PM noise 40 GHz oscillator that uses a conventional air-dielectric cavity resonator as a frequency discriminator to clean up the PM noise of a commercial 10 GHz dielectric resonator oscillator (DRO) multiplied by four. The

Low-Frequency Characterization of MEMS-Based Portable Atomic Magnetometer

June 2, 2010
Author(s)
Rahul R. Mhaskar, Svenja A. Knappe, John E. Kitching
Atomic magnetometers based on absorption or polarization rotation of light in an alkali vapor have recently demonstrated sensitivities rivaling those of superconducting quantum interference devices (SQUIDs). Miniaturization of such devices containing vapor
Displaying 2051 - 2075 of 2587
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