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Search Publications by: Roger Brown (Fed)

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Displaying 1 - 7 of 7

Statistics for quantifying aging in time transfer system delays

November 10, 2023
Author(s)
Tom Parker, Roger Brown, Jeffrey Sherman
The time delays in time transfer systems such as Two-Way Satellite Time and Frequency Transfer (TWSTFT), or GPS carrier phase (GPSCP) change over time. A double difference such as TWSTFT – GPSCP provides information on the changes in the relative time

VHF/UHF detection using high angular momentum Rydberg states

May 12, 2023
Author(s)
Roger Brown
We demonstrate resonant detection of rf electric fields from 240 MHz to 900 MHz (VHF/UHF) using electromagnetically induced transparency with orbital angular momentum, L = 3 → L′ = 4, Rydberg states. These Rydberg states are accessible with three-photon

A Resilient Architecture for the Realization and Distribution of Coordinated Universal Time to Critical Infrastructure Systems in the United States: Methodologies and Recommendations from the National Institute of Standards and Technology (NIST)

November 3, 2021
Author(s)
Jeffrey Sherman, Ladan Arissian, Roger Brown, Matthew J. Deutch, Elizabeth Donley, Vladislav Gerginov, Judah Levine, Glenn Nelson, Andrew Novick, Bijunath Patla, Tom Parker, Benjamin Stuhl, Jian Yao, William Yates, Michael A. Lombardi, Victor Zhang, Douglas Sutton
The Time and Frequency Division of the National Institute of Standards and Technology (NIST), an agency of the United States Department of Commerce (DOC), was tasked with fulfilling Section 4, Part (i) of the Position, Navigation and Timing (PNT) Executive

Modeling motional energy spectra and lattice light shifts in optical lattice clocks

May 8, 2020
Author(s)
Kyle Beloy, Will McGrew, Xiaogang Zhang, Daniele Nicolodi, Robert J. Fasano, Youssef Hassan, Roger Brown, Andrew Ludlow
We develop a model to describe the motional (i.e., external degree of freedom) energy spectra of atoms trapped in a one-dimensional optical lattice, taking into account both axial and radial confinement relative to the lattice axis. Our model respects the

First observation with global network of optical atomic clocks aimed for a dark matter detection

January 30, 2019
Author(s)
P. Wcislo, P. Ablewski, Kyle Beloy, S. Bilicki, M. Bober, Roger Brown, Robert J. Fasano, R. Ciurylo, H. Hachisu, T. Ido, J. Lodewyck, Andrew Ludlow, Will McGrew, P. Morzynski, Daniele Nicolodi, Marco Schioppo, M. Sekido, R. Le Targat, P. Wolf, Xiaogang Zhang, B. Zjawin, M. Zawada
We report on the first earth-scale quantum sensor network based on optical atomic clocks aimed at dark matter (DM) detection. Exploiting differences in the susceptibilities to the fine- structure constant of essential parts of an optical atomic clock, i.e

Ultra-stable optical clock with two cold-atom ensembles

January 1, 2017
Author(s)
Marco Schioppo, Roger Brown, Will McGrew, Nathan M. Hinkley, Robert J. Fasano, Kyle Beloy, Gianmaria Milani, Daniele Nicolodi, Jeffrey Sherman, Nate B. Phillips, Christopher W. Oates, Andrew Ludlow
Atomic clocks based on optical transitions are the most stable, and therefore precise, timekeepers available. These clocks operate by alternating intervals of atomic interrogation with ‘dead' time required for quantum state preparation and readout. This