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Search Publications

NIST Authors in Bold

Displaying 576 - 600 of 737

Soliton dynamics of an atomic spinor condensate on a Ring Lattice

March 6, 2013
Author(s)
Indubala I. Satija, Carlos L. Pando L., Eite Tiesinga
We study the dynamics of macroscopically-coherent matter waves of an ultra-cold atomic spin-1 or spinor condensate on a ring lattice of six sites and demonstrate a novel type of spatio-temporal internal Josephson effect. Using a discrete solitary mode of

Cavity optomechanics with sub-wavelength grating mirrors

December 18, 2012
Author(s)
Utku Kemiktarak, Mathieu Durand, Michael Metcalfe, John R. Lawall
We design, fabricate, and study a novel platform for cavity optomechanics: a silicon nitride membrane patterned as a sub-wavelength diffraction grating. Using the grating as one mirror of a Fabry-Perot cavity, we realize an optical finesse of $F=2830\pm 60

The Infrared Spectrum of HOOH+ Trapped in Solid Neon

October 12, 2012
Author(s)
Warren E. Thompson, Catherine L. Lugez, Marilyn E. Jacox
When a Ne:H2O2 mixture is codeposited at 4.3 K with a beam of neon atoms that have been excited in a microwave discharge, three new, photosensitive absorptions appear which can be assigned to the three infrared-active fundamentals of trans-HOOH+. When the

Interstellar Carbodiimide (HNCNH) - A New Astronomical Detection from the GBT PRIMOS Survey via Maser Emission Features

October 1, 2012
Author(s)
Brett A. McGuire, Ryan A. Loomis, Cameron M. Charness, Geoffery A. Blake, Jan M. Hollis, Francis J. Lovas, Philip R. Jewell, Anthony J. Remijan
Historically, searches for new astronomical molecules resulted in the detection of favorable, high line strength transitions based on a thermal approximation to the excitation of these species in interstellar environments. Given the temperatures of hot

Anisotropy induced Feshbach resonances in a quantum dipolar gas of magnetic atoms.

September 7, 2012
Author(s)
A Petrov, Svetlana A. Kotochigova, Eite Tiesinga
We explore the anisotropic nature of Feshbach resonances in the collision between ultracold magnetic submerged-shell dysprosium atoms, which can only occur due to couplings to rotating bound states. This is in contrast to well-studied alkali-metal atom

Solution-phase and Magnetic Approach Towards Understanding Iron Gall Inks

August 13, 2012
Author(s)
Harshita Kumari, Steven R. Kline, Cindi L. Dennis, Andrew V. Mossine, Rick L. Paul, Carol A. Deakyne, Jerry L. Atwood
Crystallization of compounds of iron with polyphenols, such as iron gall inks, has been an ongoing challenge. As with iron-gall inks, iron complexes of 1,2,3-trihydroxphenol-containing marocycles have also proved difficult to crystallize. Despite this

Towards One-electron Ions in Rydberg States for Laser Spectroscopy

July 30, 2012
Author(s)
Joseph Tan, Samuel Brewer, Nicholas D. Guise
Simple quantum systems play important roles in the determination of fundamental constants. Very recently at NIST, bare nuclei created in an EBIT were extracted and captured in a novel compact Penning trap. This is a step towards production of one-electron

Highly Charged Ions in Rare Earth Permanent Magnet Penning Traps

July 13, 2012
Author(s)
Nicholas D. Guise, Samuel Brewer, Joseph Tan
A newly constructed apparatus at the United States National Institute of Standards and Technology (NIST) is designed for the isolation, manipulation, and study of highly charged ions. Highly charged ions are produced in the NIST electron-beam ion trap

Time-Resolved Vibrational Spectroscopy of [FeFe-Hydrogenase Model Compounds

May 21, 2012
Author(s)
Edwin Heilweil, Christopher J. Stromberg
Fe2(μ-S2C3H6)(CO)6 is a model compound found to mimic the active site structure of the [FeFe]-hydrogenases. To observe the time-dependent behavior of this molecule, ultrafast ultraviolet (UV) or visible excitation with infrared (IR) probe measurements of

Effective multibody interactions of harmonically confined ultracold neutral bosons

March 21, 2012
Author(s)
Philip Johnson, W F. Flynn, D Blume, X Y. Yin, Eite Tiesinga
We use renormalized perturbation theory to calculate effective two-, three-, and four-body interactions for N neutral ultracold bosons in the ground state of an isotropic harmonic trap, assuming only two-body interactions modeled with a zero-range

Penning traps with unitary architecture for storage of highly charged ions

February 15, 2012
Author(s)
Joseph N. Tan, Samuel M. Brewer, Nicholas D. Guise
Penning traps are made extremely compact by embedding rare-earth permanent magnets in the electrode structure. Axially-oriented NdFeB magnets are used to produce 0.32 T for ion trapping in unitary architectures that functionally couple the electric and

Semiclassical fifth virial coefficients for improved ab initio helium--4 standards

February 15, 2012
Author(s)
Katherine Shaul, Andrew Schultz, David A. Kofke, Michael R. Moldover
For helium-4, we present ab initio, semi-classical calculations of virial coefficients Bn for for n = 2, 3, 4, and 5 from 50 K to 1000 K. Using our values of B4 and B5 and the more accurate literature values of B2 and B3, we argue that the ab initio virial

Mechanically Compliant Grating Reflectors for Optomechanics

February 10, 2012
Author(s)
Utku Kemiktarak, Michael Metcalfe, Mathieu Durand, John R. Lawall
We demonstrate micromechanical reflectors with a reflectivity as large as 99.4% and a mechanical quality factor Q as large as 7.8 x 10^5 for optomechanical applications. The reflectors are silicon nitride membranes patterned with sub-wavelength grating
Displaying 576 - 600 of 737
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