U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications

NIST Authors in Bold

Displaying 1151 - 1175 of 2503

Frequency response of the external quantum efficiency in multijunction solar cells

June 29, 2017
Author(s)
Nicolas Marquez Peraca, D T. Bilir, Behrang Hamadani
The frequency dependence of the external quantum efficiency (EQE) of high-quality multijunction solar cells was examined by the modulated photocurrent spectroscopy method via an optical setup comprised of a light-pipe-coupled compact LED array. The optical

A pulsed scalar optically-pumped magnetometer

June 16, 2017
Author(s)
Vladislav P. Gerginov, Sean P. Krzyzewski, Svenja A. Knappe
A scalar magnetic field sensor based on 87Rb vapor millimeter-size cell is described. The magnetometer uses co-propagating pump/probe laser beam, amplitude modulation of the pump beam and non-demolition polarization rotation detection of the probe beam

A Low-Power Reversible Alkali Atom Source

June 13, 2017
Author(s)
Songbai Kang, Russell P. Mott, Kevin A. Gilmore, Logan D. Sorenson, Matthew T. Rahker, Elizabeth A. Donley, John E. Kitching, Christopher S. Roper
An electrically-controllable, solid-state, reversible device for sourcing and sinking alkali vapor is presented. When placed inside an alkali vapor cell, both an increase and decrease of the rubidium vapor density by a factor of two are demonstrated

Self-referenced frequency combs using high-efficiency silicon nitride waveguides

June 12, 2017
Author(s)
David R. Carlson, Daniel D. Hickstein, Alexander J. Lind, Stefan Droste, Daron A. Westly, Nima Nader, Ian R. Coddington, Nathan R. Newbury, Kartik A. Srinivasan, Scott A. Diddams, Scott B. Papp
We utilize silicon nitride waveguides to self-reference telecom-wavelength fiber frequency combs through supercontinuum generation using less than 15 mW total optical average power. This is approximately ten times lower than conventional approaches using

Preservation of surface conductivity and dielectric loss tangent in large-scale, encapsulated epitaxial graphene measured by non-contact microwave cavity perturbations

May 19, 2017
Author(s)
Albert F. Rigosi, Nicholas R. Glavin, Chieh-I Liu, Yanfei Yang, Jan Obrzut, Heather M. Hill, Jiuning Hu, Hsin Y. Lee, Angela R. Hight Walker, Curt A. Richter, Randolph E. Elmquist, David B. Newell
Regarding the improvement of current quantized Hall resistance (QHR) standards, one promising avenue is the growth of homogeneous monolayer epitaxial graphene (EG). A clean and simple process was used to produce large, precise areas of EG. Properties like

High-precision measurement of the X-ray Cu K-alpha spectrum

May 12, 2017
Author(s)
Marcus H. Mendenhall, Albert Henins, Lawrence T. Hudson, Csilla I. Szabo-Foster, Donald A. Windover, James P. Cline
The structure of the x-ray emission lines of the Cu Kα complex has been remeasured on a newly commissioned instrument, in a manner directly traceable to the Système Internationale definition of the meter. In this measurement, the region from 8000 to 8100

Preparation and coherent manipulation of pure quantum states of a single molecular ion

May 11, 2017
Author(s)
Chin-Wen Chou, Christoph Kurz, David B. Hume, Philipp N. Plessow, David R. Leibrandt, Dietrich G. Leibfried
Laser cooling and trapping of atoms and atomic ions has led to breakthroughs in understanding of exotic phases of matter [1-3], development of exquisite sensors [4] and state-of-the-art atomic clocks [5]. For molecules, with their more complicated internal

Kinetic theory of dark solitons with tunable friction

May 3, 2017
Author(s)
Ian B. Spielman, Hilary Hurst, Victor Galitski
We study controllable friction in a system consisting of a dark soliton in a one-dimensional Bose- Einstein condensate coupled to a non-interacting Fermi gas. The fermions act as impurity atoms, not part of the original condensate, that scatter off of the

Improvements in Accelerometer Calibration at NIST Using Digital Vibrometry

April 29, 2017
Author(s)
Beverly F. Payne, Richard A. Allen, Colleen E. Hood
Improvements in shaker design and laser vibrometer development has provided more precise calibration of accelerometers. Calibrations are performed at frequencies from 1Hz to 20 kHz with improved uncertainty and improved efficiency. The vibrometer mounting

Detector-Independent Verification of Quantum Light

April 21, 2017
Author(s)
Jan Sperling, W.R. Clements, Andreas Eckstein, Meritt Moore, Jelmer Renema, Steven Kolthammer, Sae Woo Nam, Adriana Lita, Thomas Gerrits, Wolfgang Vogel, G.S. Agarwal, Ian Walmsley
We introduce a method for the verification of nonclassical light which is independent of the complex interaction between the generated light and the material of the detectors, which are in our work superconducting transition-edge sensors. This is achieved

The 2016 edition of the Art in Science of MicroTAS

April 21, 2017
Author(s)
Darwin R. Reyes-Hernandez
Dublin, Ireland beheld The 20th International Conference of Miniaturized Systems for Chemistry and Life Sciences (MicroTAS 2016) from October 23 to 27, 2016. The conference not only included a great technical program, but also outreach activities, an

Coherent Frequency Combs for Spectroscopy in the 3-5 Micron Region

April 18, 2017
Author(s)
Daniel I. Maser, Gabriel G. Ycas, William I. Depetri, Flavio Caldas da Cruz, Scott A. Diddams
A tunable mid-infrared frequency comb was created via diff erence frequency generation. Pulses between 1 and 1.5 μm were mixed to make idlers of 2.6-5.2 μm. Two such combs were heterodyned at 5 μm to show their coherence and potential for spectroscopy.

UV-sensitive superconducting nanowire single photon detectors for integration in an ion trap

April 17, 2017
Author(s)
Daniel H. Slichter, Varun B. Verma, Dietrich G. Leibfried, Richard P. Mirin, Sae Woo Nam, David J. Wineland
We demonstrate superconducting nanowire single photon detectors with 76 +/- 4% system detection efficiency at a wavelength of 315 nm and an operating temperature of 3.2 K, with a background count rate below 1 count per second at saturated detection

Infrared and visible laser spectroscopy for highly-charged Ni-like ions

April 12, 2017
Author(s)
Yuri Ralchenko
Application of visible or infrared (IR) lasers for spectroscopy of highly-charged ions (HCI) has not been particularly extensive so far due to a mismatch in typical energies. We show here that the energy difference between the two lowest levels within the

Hyperfine-mediated electric quadrupole shifts in Al+ and In+ ion clocks

April 6, 2017
Author(s)
Kyle P. Beloy, David R. Leibrandt, Wayne M. Itano
We evaluate the electric quadrupole moments of the 1S0 and 3P0 clock states of 27Al+ and 115In+. To capture all dominant contributions, our analysis extends through third order of perturbation theory and includes hyperfine coupling of the electrons to both

Investigation of Feshbach Resonances in ultra-cold 40K spin mixtures

April 3, 2017
Author(s)
Eite Tiesinga, J Krauser, J Heinze, S Gotze, M Lanbecker, N Flashner, L Cook, T Hanna, K Sengstock, C Becker
Magnetically-tunable Feshbach resonances are an indispensable tool for experiments with atomic quantum gases. We report on twenty thus far unpublishedi Feshbach resonances and eleven further probable Feshbach resonances in spin mixtures of ultracold

Cryogenic pulsed I-V measurements on homo- and heterojunction III-V TFETs

April 1, 2017
Author(s)
Quentin Smets, Jihong Kim, Jason Campbell, David M. Nminibapiel, Dmitry Veksler, Pragya Shrestha, Rahul Pandey, Anne S. Verhulst, Eddy Simoens, David J. Gundlach, Curt A. Richter, Kin P. Cheung, Suman Suman, Anda Mocuta, Nadine Collaert, Aaron Thean, Marc Heyns
Most experimental reports of tunneling field-effect transistors show defect-related performance degradation. Charging of oxide traps causes Fermi level pinning, and Shockley-Read-Hall (SRH)/trap-assisted tunneling (TAT) generation cause unwanted leakage

Chained Bell inequality experiment with high-efficiency measurements

March 28, 2017
Author(s)
Ting Rei Tan, Stephen D. Erickson, Peter L. Bierhorst, Daniel Kienzler, Scott C. Glancy, Emanuel H. Knill, Dietrich G. Leibfried, David J. Wineland, Yong Wan
We report correlation measurements on two 9Be+ ions that violate a chained Bell inequality obeyed by any local-realistic theory. The correlations can be modeled as derived from a mixture of a local-realistic probabilistic distribution and a distribution
Displaying 1151 - 1175 of 2503
Was this page helpful?