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Search Publications

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Displaying 451 - 475 of 727

Energy Renormalization to Coarse-Graining of the Dynamics of a Model Glass-Forming Liquid

February 5, 2018
Author(s)
Wenjie Xia, Jake Song, Nitin Hansoge, Frederick R. Phelan Jr., Sinan Keten, Jack F. Douglas
Soft condensed matters characteristically exhibit a strong temperature dependence of relaxation properties due to glass formation, but currently no effective temperature transferable coarse- graining method exists that allows for the prediction of their

Vanadium Transitions in the Spectrum of Arcturus

February 1, 2018
Author(s)
Michael P. Wood, Chris Sneden, James E. Lawler, E. A. Den Hartog, John J. Cowan, Gillian Nave
We derive a new abundance for vanadium in the bright, mildly metal-poor red giant Arcturus. This star has an excellent high-resolution spectral atlas and well-understood atmospheric parameters, and it displays a rich set of neutral vanadium lines that are

From the Mise-en-pratique for Mass to the Future of Metrology for the SI

December 1, 2017
Author(s)
Carl J. Williams
The two most troublesome issues with the SI as currently defined involve the artifact kilogram (kg) and the electrical units. Defining the kg as exactly equal to the mass of the International Prototype Kilogram (IPK) poses severe difficulties in scaling

The Future of Quantum Based Measurements and the SI

December 1, 2017
Author(s)
Carl J. Williams
The U.S. National Institute of Standards and Technology (NIST), along with other NMIs, is preparing for a new era in the history of metrology made possible by the growing use of quantum-based standards and measurements. This development will dramatically

The SI and Quantum Metrology

December 1, 2017
Author(s)
Carl J. Williams
The United States' National Institute of Standards and Technology (NIST) is playing a major role in the worldwide effort to base the International System of Units (SI) on fundamental constants. In many cases, units will be redefined in terms of invariant

Spontaneous avalanche dephasing in large Rydberg ensembles

November 13, 2017
Author(s)
Thomas L. Boulier, Eric Magnan, Carlos Bracamontes, James Maslek, Elizabeth Goldschmidt, Jeremey Young, Alexey Gorshkov, Steven Rolston, James V. Porto
Strong dipole-exchange interactions due to spontaneously produced contaminant states can trigger rapid dephasing in many-body Rydberg ensembles [E. Goldschmidt et al., PRL 116, 113001 (2016)]. Such broadening has serious implications for many proposals to

Development of a new UHV/XHV pressure standard (Cold Atom Vacuum Standard)

November 10, 2017
Author(s)
Julia Scherschligt, James A. Fedchak, Daniel Barker, Stephen Eckel, Nikolai Klimov, Constantinos Makrides, Eite Tiesinga
The National Institute of Standards and Technology has recently begun a program to develop a primary pressure standard that is based on ultra-cold atoms, covering a pressure range of 1 × 10-6 Pa to 1 × 10-10 Pa and possibly lower. These pressures

Rigidity of the magic pentagram game

November 2, 2017
Author(s)
Amir Kalev, Carl Miller
A game is rigid if a near-optimal score guarantees, under the sole assumption of the validity of quantum mechanics, that the players are using an approximately unique quantum strategy. As such, rigidity has a vital role in quantum cryptography as it

Simultaneous readout of 128 X-ray and Gamma-ray Transition-edge Microcalorimeters using Microwave SQUID Multiplexing

August 8, 2017
Author(s)
John Mates, Dan Becker, Douglas Bennett, Johnathon Gard, James P. Hays-Wehle, Joseph Fowler, Gene C. Hilton, Carl D. Reintsema, Dan Schmidt, Daniel Swetz, Leila R. Vale, Joel Ullom
The number of elements in most cryogenic sensor arrays is limited by the technology available to multiplex signals from the array into a smaller number of wires and readout amplifiers. The largest demonstrated arrays of transition-edge sensor (TES)

Noise Refocusing in a Five-blade Neutron Interferometer

August 1, 2017
Author(s)
Michael G. Huber, Muhammad D. Arif, Dimitry A. Pushin, David G. Cory, Dusan Sarenac, Joachim Nsofini, Kamyar Ghofrani
We provide a quantum information description of a proposed five-blade neutron interferometer geometry and show that it is robust against low-frequency mechanical vibrations and dephasing due to the dynamical phase. The extent to which the dynamical phase

Partial Ionization Cross Sections of Organic Molecules

June 13, 2017
Author(s)
Karl Irikura
Partial ionization cross sections are the absolute yields of specific ions from an electron- molecule collision. They are necessary for modeling plasmas and for determining the sensitivity of mass spectrometers, among other applications. One mass

Mid-infrared laser-induced fluorescence with nanosecond time resolution using a superconducting nanowire single-photon detector: New technology for molecular science

June 2, 2017
Author(s)
Li Chen, Dirk Schwarzer, Varun Verma, Martin Stevens, Francesco F. Marsili, Richard Mirin, Sae Woo Nam, Alec M. Wodtke
In contrast to UV photomultiplier tubes widely used in physical chemistry, mid- infrared detectors are notorious for poor sensitivity and slow time response. This helps explain why, despite the importance of infrared spectroscopy in molecular science, mid

The Lattice Spacing Variability of Intrinsic Float-Zone Silicon

May 11, 2017
Author(s)
Ernest G. Kessler Jr., Csilla Szabo-Foster, James Cline, Albert Henins, Lawrence T. Hudson, Marcus Mendenhall, Mark D. Vaudin
Precision lattice spacing comparison measurements at the National Institute of Standards and Technology (NIST) provide traceability of x-ray wavelength and powder diffraction standards to the international system of units (SI). Here we both summarize and

Bose-Einstein Condensates in Artificial Gauge Fields

May 1, 2017
Author(s)
Ian Spielman, Lindsay LeBlanc
Quantum mechanically, static or applied gauge fields manifest themselves by directly coupling to a system's phase. Artificial gauge field techniques manipulate the phase of a Bose-Einstein condensates's order parameter, yielding effects present in

Graphene microcapsule arrays for combinatorial electron microscopy and spectroscopy in liquids

April 27, 2017
Author(s)
Alexander Yulaev, Hongxuan Guo, Evgheni Strelcov, Lei Chen, Ivan Vlasssiouk, Andrei Kolmakov
An atomic-scale thickness, molecular impermeability, low atomic number, and mechanical strength make graphene an ideal electron transparent membrane for scanning electron microscopy and spectroscopy in liquids. Here, we present a novel sample platform made

Molecular Dynamics Simulation of Trimer Self-Assembly Under Shear

March 6, 2017
Author(s)
Raymond D. Mountain, Harold Hatch, Vincent K. Shen
The self-assembly of patchy trimer particles with one attractive bead and two repulsive beads is investigated with nonequilibrium molecular dynamics simulations in the presence of a velocity gradient, as would be produced by the application of a shear

The Cu II Spectrum

February 24, 2017
Author(s)
Alexander Kramida, Gillian Nave, Joseph Reader
New wavelength measurements in the vacuum ultraviolet (VUV), ultraviolet and visible spectral regions have been combined with available literature data to refine and extend the description of the spectrum of singly ionized copper (Cu II). In the VUV region

In situ X-ray scattering studies of the influence of an additive on the formation of a low-bandgap bulk- heterojunction

February 21, 2017
Author(s)
Felicia A. Bokel, Lee J. Richter, Sebastian Engmann, Andrew Herzing, Brian A. Collins, Hyun W. Ro, Dean DeLongchamp
The evolution of the morphology of a high-efficiency, blade-coated, organic-photovoltaic (OPV) active layer containing the low band-gap polymer poly[(4,8-bis[5-(2-ethylhexyl)thiophene-2-yl]benzo[1,2-b:4,5-b']dithiophene)-2,6-diyl-alt-(4-(2-ethylhexanoyl)

Multi-configuration Dirac-Hartree-Fock calculations of forbidden transitions within the 3d^k ground configurations of highly charged ions (Z = 72 - 83)

February 21, 2017
Author(s)
Z.L. Zhao, K. Wang, S. Li, R. Si, C.Y. Chen, J. Yan, Yuri Ralchenko
Extensive self-consistent multi-configuration Dirac-Hartree-Fock (MCDHF) calculations are performed for the 3s^2 3p^6 3d^k(k = 1−9) ground configurations of highly charged ions (Z = 72−83). Complete and consistent data sets of level energies,wavelengths
Displaying 451 - 475 of 727
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