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Search Publications by James C. Bergquist

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Displaying 1 - 25 of 110

Generation of Ultrastable microwaves via optical frequency division

Author(s)
Tara M. Fortier, Matthew S. Kirchner, Jennifer A. Taylor, James C. Bergquist, Yanyi Jiang, Andrew D. Ludlow, Christopher W. Oates, Till P. Rosenband, Scott A. Diddams, Franklyn J. Quinlan, Nathan D. Lemke
A frequency-stabilized femtosecond laser optical frequency comb serves as a source of microwave signals having very low close-to-carrier phase noise. Comparison

Field-test of a robust, portable, frequency-stable laser

Author(s)
David R. Leibrandt, Michael J. Thorpe, James C. Bergquist, Till P. Rosenband
We operate a frequency-stable laser in a non-laboratory environment where the test platform is a passenger vehicle. We measure the acceleration experienced by

Stylus ion trap for enhanced access and sensing

Author(s)
Robert Maiwald, Gerd Leuchs, Dietrich G. Leibfried, Joseph W. Britton, James C. Bergquist, David J. Wineland
We experimentally characterized a novel radio-frequency (rf) ion trap geometry formed by two concentric cylinders over a ground plane. These traps allow for

Frequency Measurements of Al+ and Hg+ Optical Standards

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, Thomas E. Parker, Scott A. Diddams, Tara M. Fortier
Frequency standards based on narrow optical transitions in 27Al+ and 199Hg+ ions have been developed at NIST. Both standards have absolute reproducibilities of

Yb Optical Lattice Clock

Author(s)
Nathan D. Lemke, Andrew D. Ludlow, Zeb Barber, N Poli, C.W. Hoyt, Long-Sheng Ma, Jason Stalnaker, Christopher W. Oates, Leo Hollberg, James C. Bergquist, A. Brusch, Tara M. Fortier, Scott A. Diddams, Thomas P. Heavner, Steven R. Jefferts, Thomas E. Parker
We describe the development and latest results of an optical lattice clock based on neutral Yb atoms, including investigations based on both even and odd

Alpha-Dot or Not: Comparison of Two Single Atom Optical Clocks

Author(s)
Till P. Rosenband, David Hume, Chin-Wen Chou, J.C. Koelemeij, A. Brusch, Sarah Bickman, Windell Oskay, Tara M. Fortier, Jason Stalnaker, Scott A. Diddams, Nathan R. Newbury, William C. Swann, Wayne M. Itano, David J. Wineland, James C. Bergquist
Repeated measurements of the frequency ratio of Hg+ and Al+ single-atom optical clocks over the course of a year yield a constraint on the possible temporal

Recent atomic clock comparisions at NIST

Author(s)
Luca Lorini, Neil Ashby, Anders Brusch, Scott A. Diddams, Robert E. Drullinger, Eric Eason, Tara M. Fortier, Pat Hastings, Thomas P. Heavner, David Hume, Wayne M. Itano, Steven R. Jefferts, Nathan R. Newbury, Thomas E. Parker, Till P. Rosenband, Jason Stalnaker, William C. Swann, David J. Wineland, James C. Bergquist
The record of atomic clock frequency comparisons at NIST over the past half-decade provides one of the tightest constraints of any present-day, temporal

Ratio of the Al+ and Hg+ Optical Clock Frequencies to 17 Decimal Places

Author(s)
Wayne M. Itano, Till P. Rosenband, David Hume, P.O. Schmidt, Chin-Wen Chou, A. Brusch, Luca Lorini, Windell Oskay, Robert E. Drullinger, Sarah Bickman, Tara M. Fortier, Jason Stalnaker, Scott A. Diddams, William C. Swann, Nathan R. Newbury, David J. Wineland, James C. Bergquist
Frequency standards (atomic clocks) based on narrow optical transitions in 27Al+ and 199Hg+ have been developed over the past several years at NIST. These two

Frequency evaluation of the doubly forbidden 1S03P0 transition in bosonic 174Yb

Author(s)
Nicola Poli, Zeb Barber, Nathan D. Lemke, Christopher W. Oates, Tara M. Fortier, Scott A. Diddams, Leo W. Hollberg, James C. Bergquist, Anders Brusch, Steven R. Jefferts, Thomas P. Heavner, Thomas E. Parker
We report an uncertainty evaluation of an optical lattice clock based on the 1S0 –3P0 transition in the bosonic isotope 174Yb using magnetically induced

Frequency ratio of Al+ and Hg+ single-ion optical clocks; metrology at the 17th decimal place

Author(s)
Till P. Rosenband, David Hume, P. O. Schmidt, Chin-Wen Chou, Anders Brusch, Luca Lorini, Windell Oskay, Robert E. Drullinger, Tara M. Fortier, Jason Stalnaker, Scott A. Diddams, Nathan R. Newbury, W Swann, Wayne M. Itano, David J. Wineland, James C. Bergquist
We report the frequency ratio of the two most accurate and stable atomic clocks with a total fractional uncertainty of 5.2 X 10-17 . This frequency ratio is the

Optical-to-microwave frequency comparison with fractional uncertainty of 10-15

Author(s)
Jason Stalnaker, Scott A. Diddams, Tara M. Fortier, K Kim, Leo W. Hollberg, James C. Bergquist, Wayne M. Itano, Marie Delaney, Luca Lorini, Windell Oskay, Thomas P. Heavner, Steven R. Jefferts, Filippo Levi, Thomas E. Parker, Jon H. Shirley
We report the technical aspects of the optical-to-microwave comparison for our recent measurements of the optical frequency of the mercury single-ion frequency

Optical frequency standards based on mercury and aluminum ions

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
Single-trapped-ion frequency standards based on a 282 nm transition in 199Hg+ and on a 267 nm transition in 27Al+ have been developed at NIST over the past

Frequency Comparison of Al+ and Hg+ Optical Standards

Author(s)
Till P. Rosenband, David Hume, Anders Brusch, Luca Lorini, P. O. Schmidt, Tara M. Fortier, Jason Stalnaker, Scott A. Diddams, Nathan R. Newbury, W Swann, Windell Oskay, Wayne M. Itano, David J. Wineland, James C. Bergquist
We compare the frequencies of two single ion frequency standards: 27Al+ and 199Hg+. Systematic fractional frequency uncertainties of both standards are below 10

Observation of the 1S0-3P0 clock transition in 27Al+

Author(s)
Till P. Rosenband, P. O. Schmidt, David Hume, Wayne M. Itano, Tara M. Fortier, Jason Stalnaker, Scott A. Diddams, Jeroen Koelemeij, James C. Bergquist, David J. Wineland
We report for the first time, laser spectroscopy of the 1S0 – 3P0 clock transition in 27Al+. A single aluminum ion and a single beryllium ion are simultaneously

Improved Limits on Variation of the Fine Structure Constant and Violation of Local Position Invariance

Author(s)
Tara M. Fortier, Neil Ashby, James C. Bergquist, Marie Delaney, Scott A. Diddams, Thomas P. Heavner, Leo W. Hollberg, Wayne M. Itano, Steven R. Jefferts, K Kim, Windell Oskay, Thomas E. Parker, Jon H. Shirley, Jason Stalnaker, Filippo Levi, Luca Lorini
We report tests of Local Position Invariance (LPI) and constancy of fundamental constants from measurements of the frequency ratio of the 282-nm 199Hg+ optical

Precision Atomic Spectroscopy for Improved Limits on Variation of the Fine Structure Constant and Local Position Invariance

Author(s)
Tara M. Fortier, Jason Stalnaker, Scott A. Diddams, Neil Ashby, Luca Lorini, Windell Oskay, Marie Delaney, James C. Bergquist, Steven R. Jefferts, Thomas E. Parker, Thomas P. Heavner, Filippo Levi, Jon H. Shirley, Wayne M. Itano, Kyoungsik Kim, Leo W. Hollberg
We report tests of local position invariance (LPI) and the constancy of fundamental constants from measurements of the frequency ratio of the 282-nm $^{199}$Hg$

Trapped atomic ions and quantum information processing

Author(s)
David J. Wineland, Dietrich G. Leibfried, James C. Bergquist, Brad R. Blakestad, John J. Bollinger, Joseph W. Britton, J Chiaverini, Ryan Epstein, David Hume, Wayne M. Itano, John D. Jost, Emanuel H. Knill, Jeroen Koelemeij, C. Langer, R Ozeri, Rainer Reichle, Till P. Rosenband, Tobias Schaetz, Piet Schmidt, Signe Seidelin, Nobuyasu Shiga, Janus Wesenberg
The basic requirements for quantum computing and quantum simulation (Single- and multi-qubit gates, long memor times, etc.)have been demonstrated in separate

A single-atom optical clock with high accuracy

Author(s)
Windell Oskay, Scott A. Diddams, Elizabeth A. Donley, Tara M. Fortier, Thomas P. Heavner, Leo W. Hollberg, Wayne M. Itano, Steven R. Jefferts, M J. Jensen, Kyoungsik Kim, F Levi, Thomas E. Parker, James C. Bergquist
For the past fifty years, atomic frequency standards based on the cesium ground-state hyperfine splitting have been the most accurate timepieces in the world

Spectroscopy of atomic and molecular ions using quantum logic

Author(s)
Piet Schmidt, Till P. Rosenband, Jeroen Koelemeij, David Hume, Wayne M. Itano, James C. Bergquist, David J. Wineland
Recently developed techniques for quantum computation using trapped ions allow unprecedented coherent control of the internal and external states of single