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Search Publications by: Chin-wen Chou (Fed)

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Displaying 1 - 24 of 24

Lifetime-Limited Interrogation of Two Independent 27Al+ Clocks using Correlation Spectroscopy

December 9, 2020
Author(s)
Ethan Clements, May E. Kim, Kaifeng Cui, Aaron M. Hankin, Samuel M. Brewer, Jose Valencia, Jwo-Sy Chen, Chin-wen Chou, David Leibrandt, David Hume
Laser decoherence limits the stability of optical clocks by broadening the observable resonance linewidths and adding noise during the dead time between clock probes. Correlation spectroscopy avoids these limitations by measuring correlated atomic

Quantum entanglement between an atom and a molecule

May 20, 2020
Author(s)
Yiheng Lin, David Leibrandt, Dietrich Leibfried, Chin-wen Chou
Expanding quantum control to a broad range of physical systems paves the way for advances in various aspects of science and technology, such as stringent tests of fundamental physics, quantum-enhanced sensors, and quantum information processing

Frequency-comb spectroscopy on pure quantum states of a single molecular ion

March 27, 2020
Author(s)
Chin-wen Chou, Alejandra L. Collopy, Christoph Kurz, Yiheng Lin, Michael E. Harding, Philipp N. Plessow, Tara M. Fortier, Scott A. Diddams, Dietrich G. Leibfried, David R. Leibrandt
Spectroscopy is a powerful tool for studying molecular properties and is commonly performed on large thermal ensembles of molecules that are perturbed by motional shifts and interactions with the environment and one another, resulting in convoluted spectra

Systematic uncertainty due to background-gas collisions in trapped-ion optical clocks

September 30, 2019
Author(s)
Aaron M. Hankin, Ethan Clements, Huang Yao, Samuel M. Brewer, Jwo-Sy Chen, Chin-wen Chou, David Hume, David Leibrandt
We describe a framework for calculating the frequency shift and uncertainty of trapped-ion optical atomic clocks caused by background-gas collisions, and apply this framework to an 27Al+ quantum-logic clock to enable a total fractional systematic

An 27 Al+ quantum-logic clock with systematic uncertainty below 10 -18

July 15, 2019
Author(s)
Samuel M. Brewer, Jwo-Sy Chen, Aaron M. Hankin, Ethan Clements, Chin-wen Chou, David J. Wineland, David Hume, David Leibrandt
We describe an optical atomic clock based on quantum-logic spectroscopy of the 1S 0 3P 0 transition in 27Al + with a systematic uncertainty of 9.0 x 10-19 and a frequency stability of 1.2 X 10 -15/(T 1/2). A 25Mg + ion is simultaneously trapped with the

Measurements of 25 Mg + and 27 Al + magnetic constants for improved ion clock accuracy

July 15, 2019
Author(s)
Samuel M. Brewer, Jwo-Sy Chen, Aaron M. Hankin, Ethan Clements, Chin-wen Chou, Kyle Beloy, Will McGrew, Xiaogang Zhang, Robert J. Fasano, Daniele Nicolodi, Holly Leopardi, Tara Fortier, Scott Diddams, Andrew Ludlow, David J. Wineland, David Leibrandt, David Hume
We have measured the quadratic Zeeman coefficient for the 3P0 excited electronic state in 27Al+, C2=-71.944(24) MHz/T2 and the hyperfine constant of the 25Mg+ 2S1/2 ground electronic state, Ahfs = -596 254 250.981(45) Hz, with improved uncertainties. Both

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

Sympathetic Ground State Cooling and Time-dilation Shifts in an 27Al+ Optical Clock

February 3, 2017
Author(s)
Jwo-Sy Chen, Samuel M. Brewer, David B. Hume, Chin-Wen Chou, David J. Wineland, David R. Leibrandt
We report Raman sideband cooling of 25Mg+ to sympathetically cool the secular modes of motion in a 25Mg+-27Al+ two-ion pair to near the three-dimensional (3D) ground state. The evolution of the Fock state distributions during the cooling process is studied

Trapped-ion optical atomic clocks at the quantum limits

January 31, 2017
Author(s)
David R. Leibrandt, Samuel M. Brewer, Jwo-Sy Chen, Aaron M. Hankin, David B. Hume, David J. Wineland, Chin-Wen Chou
Frequency and its inverse, time, are the most accurately measured quantities. Historically, improvements in the accuracy of clocks have enabled advances in navigation, communication, and science. Since 1967, the definition of the SI second has been based

Sub-femtosecond absolute timing jitter with a 10 GHz hybrid photonic-microwave oscillator

June 7, 2012
Author(s)
Tara M. Fortier, Craig W. Nelson, Archita Hati, Franklyn J. Quinlan, Jennifer A. Taylor, Haifeng (. Jiang, Chin-Wen Chou, Till P. Rosenband, Nathan D. Lemke, Andrew D. Ludlow, David A. Howe, Christopher W. Oates, Scott A. Diddams
We present an optical-electronic approach to generating microwave signals with high spectral purity. By overcoming shot noise and operating near fundamental thermal limits, we demonstrate 10 GHz signals that have timing deviation from an ideal periodic

A hybrid 10 GHz photonic-microwave oscillator with sub-femtosecond absolute timing jitter

May 24, 2012
Author(s)
Tara M. Fortier, Craig W. Nelson, Archita Hati, Franklyn J. Quinlan, Jennifer A. Taylor, Haifeng (. Jiang, Chin-Wen Chou, Nathan D. Lemke, Andrew D. Ludlow, David A. Howe, Christopher W. Oates, Scott A. Diddams
We demonstrate a 10 GHz hybrid oscillator comprised of a phase stabilized optical frequency comb divider and a room temperature dielectric sapphire oscillator. Characterization of the 10 GHz microwave signal via comparison of two independent hybrid

Trapped-Ion State Detection through Coherent Motion

December 9, 2011
Author(s)
Till P. Rosenband, David Hume, Chin-Wen Chou, David R. Leibrandt, Michael J. Thorpe, David J. Wineland
Coherent control of trapped atomic ions has led to several recent advances in quantum information processing 1 and precision spectroscopy 2. A basic requirement for these and other quantum-metrology experiments is the ability to detect the state of an

Quamtum coherence between two atoms beyond Q=10 15

April 22, 2011
Author(s)
Chin-Wen Chou, David Hume, Michael J. Thorpe, David J. Wineland, Till P. Rosenband
We place two atoms in quantum superposition states and observe coherent phase evolution for 3.4 × 10 15 cycles. Correlation signals from the two atoms yield information about their relative phase even after the probe radiation has decohered. This technique

Relativity and Optical Clocks

September 24, 2010
Author(s)
Chin-Wen Chou, David Hume, Till P. Rosenband, David J. Wineland
Albert Einstein's theory of relativity forced us to alter our concepts of reality. One of the more startling outcomes of the theory is that we have to give up our notions of simultaneity. This is manifest in the so-called twin paradox in which a twin

Frequency Comparison of Two High-Accuracy Al+ Optical Clocks

February 17, 2010
Author(s)
Chin-Wen Chou, David Hume, J.C. Koelemeij, David J. Wineland, Till P. Rosenband
We have constructed an optical clock with a fractional frequency inaccuracy of 8.6e-18, based on quantum logic spectroscopy of an Al+ ion. A simultaneously trapped Mg+ ion serves to sympathetically laser-cool the Al+ ion and detect its quantum state. The

Preparation of Dicke States in an Ion Chain

November 2, 2009
Author(s)
David Hume, Chin-Wen Chou, Till P. Rosenband, David J. Wineland
We have investigated theoretically and experimentally a method for preparing Dicke states in trapped atomic ions. We consider a linear chain of N ion qubits that is prepared in a particular Fock state of motion, jmi. The m phonons are removed by applying a

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

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

October 5, 2008
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 variation of the fine-structure constant a. The time variation of the measured ratio corresponds

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

August 25, 2008
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 types of standards are both based on single ions confined in Paul traps, but differ in the

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

March 6, 2008
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 best-known physical constant that is not a simple integer. Repeated measurements during the