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NIST Authors in Bold

Displaying 576 - 600 of 672

Towards a compact cold atom frequency standard based on coherent populatoin trapping

June 2, 2010
Author(s)
Francois-Xavier R. Esnault, Elizabeth Donley, John Kitching
We describe in this paper the main features of a cold atom CPT based frequency standard. We explain our particular CPT configuration and our experimental setup. as well as present simulations of the expected performance (stability and major systematics)

Feshbach resonances in ultracold gases

April 29, 2010
Author(s)
Chin P. Cheng, R Grimm, Paul S. Julienne, Eite Tiesinga
Feshbach resonances are the essential tool to control the interaction between atoms in ultracold quantum gases. They have found manifold experimental applications, opening up the way to important breakthroughs. This Review gives a broad coverage of the

Multi-level Spectroscopy of Two-Level Systems Coupled to a dc SQUID Phase Qubit

April 7, 2010
Author(s)
T. A. Palomaki, S. K. Dutta, R M. Lewis, A J. Przybysz, B. K. Cooper, H. Kwon, J. R. Anderson, C. J. Lobb, F. C. Wellstood, Eite Tiesinga
We report spectroscopic measurements of discrete two-level systems (TLSs) coupled to a dc SQUID phase qubit with a 16 μm2 area Al/AlOx/Al junction. Applying microwaves in the 10 GHz to 11 GHz range, we found eight avoided level crossings with splitting

Fundamental constants and tests of theory in Rydberg states of one-electron ions

March 19, 2010
Author(s)
Ulrich D. Jentschura, Peter Mohr, Joseph N. Tan
The nature of the theory of circular Rydberg states of hydrogenlike ions allows highly-accurate predictions to be made for energy levels. In particular, uncertainties arising from the problematic nuclear size correction which beset low angular-momentum

Symmetry and Fourier analysis of the ab-initio-determined torsional variation of structural and Hessian-related quantities for application to vibration-torsion-rotation interactions in CH3OH

January 11, 2010
Author(s)
Li-Hong Xu, Jon T. Hougen, Jonathan M. Fisher, Ronald M. Lees
The aim of the present paper is to investigate the use of quantum chemistry calculations to obtain the torsional dependence of various structural and vibrational-force-field-related quantities that could help in estimating the vibration-torsion-rotation

Radiofrequency dressing of multiple Feshbach resonances

November 3, 2009
Author(s)
A M. Kaufman, R P. Anderson, Thomas Hanna, Eite Tiesinga, Paul S. Julienne, D S. Hall
We demonstrate and explain the coupling of several proximate Feshbach resonances in $^87}$Rb using radiofrequency (rf) radiation. We present accurate measurements of the resonances and observe the changes in the scattering properties that arise through the

Radiofrequency dressing of multiple Feshbach resonances

November 3, 2009
Author(s)
A M. Kaufman, R P. Anderson, Thomas Hanna, Eite Tiesinga, Paul S. Julienne, D S. Hall
We demonstrate and explain the coupling of several proximate Feshbach resonances in $^87}$Rb using radiofrequency (rf) radiation. We present accurate measurements of the resonances and observe the changes in the scattering properties that arise through the

Quantum walk on a line for a trapped ion

October 30, 2009
Author(s)
Peng Xue, Barry Sanders, Dietrich Leibfried
We show how a quantum walk can be experimentally realized for a single trapped ion and how to interpolate between the quantum and random walk by randomizing the phase of a generalized Hadamard coin flip. The signature of the quantum walk is manifested not

Submillimeter Spectrum and Analysis of Vibrational and Hyperfine Coupling Effects in (HI)2

October 1, 2009
Author(s)
Laurent H. Coudert, Sergei P. Belov, F. Willaert, B. McElmurry, R. Lucchese, John W. Bevan, Jon T. Hougen
Observed rotational-vibrational transitions of HI dimer in the geared bending mode, centered at 511.9 GHz, are reported. This 50 kHz high resolution spectrum was recorded using a co-axially configured pulsed jet submillimeter spectrometer and the hyperfine

Effective three-body interactions of neutral atoms in optical lattices

September 15, 2009
Author(s)
Philip Johnson, Eite Tiesinga, James V. Porto, Carl J. Williams
We show that virtual excitations of neutral bosons to higher vibrational states in a three dimensional optical lattice generate effective, tunable, attractive three-body interactions. These effective processes can quickly decohere coherent states held in

Fundamental constants and tests of theory in Rydberg states of hydrogenlike ions

July 1, 2009
Author(s)
Ulrich D. Jentschura, Peter Mohr, Joseph N. Tan, Benedikt J. Wundt
A comparison of precision frequency measurements to quantum electrodynamic (QED) theoretical predictions can be used to test theory and to obtain information regarding fundamental constants. We find that for Rydberg states, theoretical uncertainties due to

Optimal Surface-Electrode Trap Lattices for Quantum Simulation with Trapped Ions

June 12, 2009
Author(s)
Roman Schmied , Janus H. Wesenberg, Dietrich Leibfried
Trapped ions offer long internal state (spin) coherence times and strong inter-particle interactions mediated by the Coulomb force. This makes them interesting candidates for quantum simulation of coupled lattices. To this end it is desirable to be able to

Frequency Measurements of Al+ and Hg+ Optical Standards

June 8, 2009
Author(s)
Wayne M. Itano, James C. Bergquist, Till P. Rosenband, David J. Wineland, David Hume, Chin-wen Chou, Steven R. Jefferts, Thomas P. Heavner, Tom Parker, Scott Diddams, Tara Fortier
Frequency standards based on narrow optical transitions in 27Al+ and 199Hg+ ions have been developed at NIST. Both standards have absolute reproducibilities of a few parts in 10 17. This is about an order of magnitude better than the fractional uncertainty

Multi-channel modeling of the formation of vibrationally cold polar KRb molecules.

May 14, 2009
Author(s)
Svetlana Kotochigova, Eite Tiesinga, Paul S. Julienne
We describe the theoretical advances that influenced the experimental creation of vibrationally and translationally cold polar 40K87Rb molecules [Nature Phys. 4, 622 (2008), Science 322, 231 (2008)]. Cold molecules were created from very-weakly bound

Observation of a 2D Bose-gas: from thermal to fractured quasi-condensate to superfluid

May 1, 2009
Author(s)
Pierre Clade, Changhyun Ryu, Anand Ramanathan, Kristian Helmerson, William D. Phillips
This paper presents experimental results on a Bose gas in a quasi-2D geometry near the Berezinskii,Kosterlitz and Thouless (BKT) transition temperature. By measuring the density profile, in situ and after time of flight, and the coherence length of the gas

Electromagnetically induced transparency in a superconducting three-level system

April 16, 2009
Author(s)
Mika Sillanpaa, Katarina Cicak, Fabio Altomare, Jae Park, Raymond Simmonds, Jian Li, G. S. Paraoanu, Pertti Hakonen
When a three-level quantum system is irradiated by an intense coupling field resonant with two of the three possible transitions, the resonant absorption of the system from its ground state by an additional radiation field is suppressed. This effect, where

Optical detection of NMR J -spectra at zero magnetic field

March 28, 2009
Author(s)
M Ledbetter, C.W. Crawford, A Pines, D.E. Wemmer, Svenja A. Knappe, John Kitching, D Budker
Nuclear magnetic resonance (NMR) has emerged as one of the most powerful analytical tools for elucidating molecular structure. One of the parameters typically extracted from NMR spectra which is necessary to fully understand the structure of a molecule is
Displaying 576 - 600 of 672
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