175 citations · 271 across the 11 of their papers we have counts for
11 papers
Atomic clock frequency ratios with fractional uncertainty
Alexander Aeppli, Willa J. Arthur-Dworschack, Kyle Beloy +24
We report high-precision frequency ratio measurements between optical atomic clocks based on Al, Yb, and Sr. With total fractional uncertainties at or bel…
Cryogenic Optical Lattice Clock with Blackbody Radiation Stark Uncertainty
Youssef S. Hassan, Kyle Beloy, Jacob L. Siegel +9
Controlling the Stark perturbation from ambient thermal radiation is key to advancing the performance of many atomic frequency standards, including state-of-the-art optical lattice…
Lattice Light Shift Evaluations In a Dual-Ensemble Yb Optical Lattice Clock
Tobias Bothwell, Benjamin D. Hunt, Jacob L. Siegel +9
In state-of-the-art optical lattice clocks, beyond-electric-dipole polarizability terms lead to a break-down of magic wavelength trapping. In this Letter, we report a novel approac…
Clock-line-mediated Sisyphus Cooling
Chun-Chia Chen, Jacob L. Siegel, Benjamin D. Hunt +6
We demonstrate sub-recoil Sisyphus cooling using the long-lived clock state in alkaline-earth-like ytterbium. A 1388 nm optical standing wave nearly resonant w…
Ratchet Loading and Multi-Ensemble Operation in an Optical Lattice Clock
Youssef S. Hassan, Takumi Kobayashi, Tobias Bothwell +6
We demonstrate programmable control over the spatial distribution of ultra-cold atoms confined in an optical lattice. The control is facilitated through a combination of spatial ma…
Excited-Band Coherent Delocalization for Improved Optical Lattice Clock Performance
Jacob Siegel, William McGrew, Youssef Hassan +5
We implement coherent delocalization as a tool for improving the two primary metrics of atomic clock performance: systematic uncertainty and instability. By decreasing atomic densi…
Sub-recoil clock-transition laser cooling enabling shallow optical lattice clocks
X. Zhang, K. Beloy, Y. S. Hassan +5
Laser cooling is a key ingredient for quantum control of atomic systems in a variety of settings. In divalent atoms, two-stage Doppler cooling is typically used to bring atoms to t…
Optical coherence between atomic species at the second scale: improved clock comparisons via differential spectroscopy
May E. Kim, William F. McGrew, Nicholas V. Nardelli +9
Comparisons of high-accuracy optical atomic clocks \cite{Ludlow2015} are essential for precision tests of fundamental physics \cite{Safronova2018}, relativistic geodesy \cite{McGre…
Frequency Ratio Measurements with 18-digit Accuracy Using a Network of Optical Clocks
Boulder Atomic Clock Optical Network, Collaboration, : +35
Atomic clocks occupy a unique position in measurement science, exhibiting higher accuracy than any other measurement standard and underpinning six out of seven base units in the SI…
Modeling motional energy spectra and lattice light shifts in optical lattice clocks
K. Beloy, W. F. McGrew, X. Zhang +5
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…
Coherent Optical Clock Down-Conversion for Microwave Frequencies with 10-18 Instability
Takuma Nakamura, Josue Davila-Rodriguez, Holly Leopardi +12
Optical atomic clocks are poised to redefine the SI second, thanks to stability and accuracy more than one hundred times better than the current microwave atomic clock standard. Ho…