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Search Publications

NIST Authors in Bold

Displaying 226 - 250 of 4257

Kinetic-energy Distributions of Positive and Negative Ions in Townsend Discharges in Oxygen

April 1, 1999
Author(s)
MVVS. Rao, Richard J. Van Brunt, James K. Olthoff
… flux-energy distributions of positive and negative ions have been measured at high electric field-to-gas density … dominant ion-molecule collision process. The less abundant ions, O + , O 2 - , and O - , exhibit non-Mawellian ion … Kinetic-energy Distributions of Positive and Negative Ions in Townsend Discharges in Oxygen …

Simplified motional heating rate measurements of trapped ions

September 19, 2007
Author(s)
Ryan Epstein, Signe Seidelin, Dietrich G. Leibfried, Janus Wesenberg, John J. Bollinger, Jason Amini, Brad R. Blakestad, Joseph W. Britton, Jonathan Home, Wayne M. Itano, John D. Jost, Emanuel H. Knill, C. Langer, R. Ozeri, Nobuyasu Shiga, David J. Wineland
… We measure motional heating rates of trapped atomic ions, a factor that influences multi-ion quantum logic gate … trap, made of gold on fused quartz, which traps ions 40~$\mu$m above its surface. Heating rates obtained from … Simplified motional heating rate measurements of trapped ions …

Clementite's Elastic Constants

October 16, 2008
Author(s)
Sudook A. Kim, H M. Ledbetter
… elastic constants differ little from those of pure b.c.c. iron and are about ten percent higher for a shear mode such … all previous reports, we find Fe 3 C stiffer than pure α-iron. … carbon, carbon steel, cementite, elastic constants, iron, iron-carbon alloy, pearlite, steel …

Two-dimensional imaging and modification of nanophotonic resonator modes using a focused ion beam

November 20, 2017
Author(s)
William R. McGehee, Thomas Michels, Vladimir A. Aksyuk, Jabez J. McClelland
… microdisk resonators using a pulsed, low-energy focused ion beam of Li+. The ion beam locally modifies the resonator structure, causing … optical resonances. Images are acquired by rastering the ion beam across the disk surface and extracting the maximum … nanophotonics, focused ion beam, microdisk resonator, imaging …

Magnetic Tunnel Junctions Fabricated Using Ion Neutralization Energy as a Tool

July 25, 2011
Author(s)
Joshua M. Pomeroy, Holger Grube, Pei-Ling Sun, Yun-Che Wang, Russell E. Lake
… degree of freedom in the devices’ fabrication. While most ion species used in common semiconductor processes (like … Highly Charged Ions, Magnetic tunnel junctions, Ion-solid interactions … Magnetic Tunnel Junctions Fabricated Using Ion Neutralization Energy as a Tool …

Individual qubit addressing of rotating ion crystals in a Penning trap

July 25, 2022
Author(s)
Anthony M. Polloreno, Ana Maria Rey, John J. Bollinger
… information processing. Scaling to larger numbers of ion qubits, potentially solved by photonic interconnects … of a strong magnetic field. However, the rotation of the ion crystal makes single ion addressability, a capability desirable for general … deformable mirror, trapped-ion quantum information processing, Penning trap, wave front …

The Potentials of Helium Ion Microscopy for Semiconductor Process Metrology

February 6, 2008
Author(s)
Michael T. Postek, Andras Vladar
… to monitor and control the manufacturing process. Helium Ion Microscopy (HIM) presents a new approach to process … the helium ions, it is theoretically possible to focus the ion beam into a smaller probe size relative to that of an … voltage and materials involved. Conversely, the helium ion beam interacts with the sample, but it does not have as …

The Helium Ion Microscope: A New Tool for Nanotechnology and Nanomanufacturing

September 1, 2007
Author(s)
Michael T. Postek, Andras Vladar, John A. Kramar, L A. Stern, John Notte, Sean McVey
… Helium Ion Microscopy (HIM) is a new, potentially disruptive … the helium ions, it is theoretically possible to focus the ion beam into a smaller probe size relative to that of an … voltage and materials involved. Conversely, the helium ion beam interacts with the sample, but it does not have as …

Elemental and Molecular Imaging of Human Hair Using Secondary Ion Mass Spectrometry

April 1, 1999
Author(s)
John G. Gillen, S V. Roberson, C M. Ng, M Stranick
… Secondary ion mass spectrometry (SIMS) is used to image the spatial … using a magnetic sector SIMS instrument operated as an ion microprobe. Analysis of electrically insulating, … spatial resolution elemental and molecular secondary ion images to be obtained from hair samples without metallic …

Reaction of Arylium Ions with the Collision Gas N2 in Electrospray Ionization Mass Spectrometry

January 9, 2015
Author(s)
Yuxue Liang, Pedatsur Neta, Yamil Simon, Stephen E. Stein
… Such peaks were found to be due to reaction of arylium ions with N2 in the collision cell. Therefore, this reaction … m/z values in an Orbitrap Elite instrument. Arylium ions were found to react with N2 in the collision cell. The … by MS3 studies, by comparison with authentic diazonium ions, and by the pressure dependence of the product ion …

Errors in trapped-ion quantum gates due to spontaneous photon scattering

April 27, 2007
Author(s)
R Ozeri, Wayne M. Itano, Brad R. Blakestad, Joseph W. Britton, J Chiaverini, John D. Jost, C. Langer, Dietrich G. Leibfried, Rainer Reichle, Signe Seidelin, Janus Wesenberg, David J. Wineland
… We analyze the error in trapped-ion, hyperfine qubit, quantum gates due to spontaneous … the gate laser beams. We investigate the error in single-ion-qubit rotations that are based on stimulated Raman transitions and in two-ion-qubit entangling phase-gates that are based on …

Stylus ion trap for enhanced access and sensing

August 1, 2009
Author(s)
Robert Maiwald, Gerd Leuchs, Dietrich Leibfried, Joseph W. Britton, James C. Bergquist, David J. Wineland
… experimentally characterized a novel radio-frequency (rf) ion trap geometry formed by two concentric cylinders over a … ion trap, laser cooling, optical access, quantum optics, … Stylus ion trap for enhanced access and sensing …

Highly mechanosensitive ion channels from graphene-embedded crown ethers

November 26, 2018
Author(s)
Alta Y. Fang, Kenneth Kroenlein, Demian Riccardi, Alexander Smolyanitsky
… and dissolved metal ions to demonstrate graphene-based ion channels highly sensitive to externally applied lattice … simulations of the effects of tensile lattice strain on ion permeation across graphene-embedded crown ether pores. … Our findings suggest the first instance of solid-state ion channels with an exponential permeation sensitivity to …

Gold Nanostructures Created by Highly Charged Ions

June 28, 2007
Author(s)
Joshua M. Pomeroy, Holger Grube, A C. Perrella, John D. Gillaspy
… by scanning tunnelling microscopy (STM). Highly charged ions, e.g.,Bi$^{81+}$, represent an exotic form of … gold, highly charged ions, nano-feature, scanning tunneling microscopy … Gold Nanostructures Created by Highly Charged Ions …

Compatibility of trapped ions and dielectrics at cryogenic temperatures

November 17, 2025
Author(s)
Margaret Bruff, Lindsay Sonderhouse, Kaitlyn David, Daniel Slichter, Dietrich Leibfried, Jules Stuart
… quantum networking, trapped ions, optical cavities, integrated photonics, quantum … Compatibility of trapped ions and dielectrics at cryogenic temperatures …

Microcalorimeter/EBIT Measurements of X-Ray Spectra of Highly Charged Ions

January 1, 2001
Author(s)
I Kink, J M. Laming, E Takacs, James V. Porto, John D. Gillaspy, E Silver, H. Schnopper, Simon R. Bandler, M Barbera, N Brickhouse, S Murray, D Landis, J. Beeman, E. E. Haller
… Spectra of highly charged Ar, Kr, Xe and Fe ions, produced in an Electron Beam Ion Trap (EBIT), have been … Kr and to determine a charge state distribution of Kr ions inside the EBIT. Line intensity ratios of Fe XVII have … EBIT, highly charged ions, microcalorimeter, x-ray spectra …

Optical frequency standards based on mercury and aluminum ions

September 12, 2007
Author(s)
Wayne M. Itano, James C. Bergquist, Anders Brusch, Scott A. Diddams, Tara M. Fortier, Thomas P. Heavner, Leo W. Hollberg, David Hume, Steven R. Jefferts, Luca Lorini, Thomas E. Parker, Till P. Rosenband, Jason Stalnaker
… Optical frequency standards based on mercury and aluminum ions …

Mechanosensitive ion permeation across sub-nanoporous MoS2 monolayers

January 23, 2019
Author(s)
Alta Y. Fang, Kenneth Kroenlein, Alexander Smolyanitsky
… functional theory calculations to investigate aqueous ion transport across subnanoporous monolayer molybdenum … pores that are permeable when unstrained, we demonstrate ion current modulation by a factor of over 20 in the tensile … be a strain-induced reduction of the generally repulsive ion–pore interactions resulting from the ions' short-range …

Aqueous Ion trapping and transport in graphene-embedded 18-crown-6 ether pores

June 25, 2018
Author(s)
Alexander Smolyanitsky, Eugene Paulechka, Kenneth Kroenlein
… in permeation between ionic species arise. The trapped ion occupancy and permeation behaviors are shown to be highly … the possibility of performing conceptually straightforward ion-based logical operations resulting from controllable … graphene are possible, suggesting utility in cascaded ion-based logic circuitry. Our results indicate that in …

Stretch-inactivated ion transport through subnanoporous two-dimensional membranes

October 3, 2024
Author(s)
Yechan Noh, Alex Smolyanitsky
… In biology, mechanosensitive ion channels facilitate the conversion of mechanical stimuli, … membranes. Here we describe an opposite behavior, in which ion transport is inactivated upon stretching a subnanoporous 2D membrane. We explore electrophoretic ion transport through several subnanoporous membranes using …

Defect Evolution of Ion-Exposed Single-Wall Carbon Nanotubes

January 3, 2019
Author(s)
Jana Kalbacova, Elias J. Garratt, Raul D. Rodriguez, Angela R. Hight Walker, Kevin A. Twedt, Jeffrey Fagan, Teresa I. Madeira, Jabez J. McClelland, Babak Nikoobakht, Dietrich R. Zahn
… defects in single-wall carbon nanotubes by a focused ion beam of light and heavy ions, Li+ and Ga+, respectively. … Precise control of defects was achieved by tuning the ion fluence over five orders of magnitude from 3∙1010 … This is further explored in a model that accounts for the ion type and its energy and thus can be employed to estimate …
Displaying 226 - 250 of 4257
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