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Enhancing Divalent Optical Atomic Clocks with the Transition
Matthew A. Bohman, Sergey G. Porsev, David B. Hume +2
Divalent atoms and ions with a singlet ground state and triplet excited state form the basis of many high-precision optical atomic clocks. Along with the metastable $^{3}\m…
Contribution of negative-energy states to multipolar polarizabilities of the Sr optical lattice clock
S. G. Porsev, M. G. Kozlov, M. S. Safronova
We address the problem of lattice light shifts in the Sr clock caused by multipolar M1 and E2 atom-field interactions. We presented a simple but accurate formula for the magnetic-d…
Motional ground-state cooling of single atoms in state-dependent optical tweezers
Christian Hölzl, Aaron Götzelmann, Moritz Wirth +3
Laser cooling of single atoms in optical tweezers is a prerequisite for neutral atom quantum computing and simulation. Resolved sideband cooling comprises a well-established method…
A Portal for High-Precision Atomic Data and Computation: Design and Best Practices
Parinaz Barakhshan, Akshay Bhosale, Amani Kiruga +3
The Atom portal, udel.edu/atom, provides the scientific community with easily accessible high-quality data about properties of atoms and ions, such as energies, transition matrix e…
Prospects of a thousand-ion Sn Coulomb-crystal clock with sub- inaccuracy
David R. Leibrandt, Sergey G. Porsev, Charles Cheung +1
We propose a many-ion optical atomic clock based on three-dimensional Coulomb crystals of order one thousand Sn ions confined in a linear RF Paul trap. Sn has a uniqu…
Calculation of energies and hyperfine structure constants of 233U^+ and 233U
S. G. Porsev, C. Cheung, M. S. Safronova
We carried out calculations of the energies and magnetic dipole hyperfine structure constants of the low-lying states of 233U^+ and 233U using two different approaches. With six va…
New Measurement Resolves Key Astrophysical Fe XVII Oscillator Strength Problem
Steffen Kühn, Charles Cheung, Natalia S. Oreshkina +19
One of the most enduring and intensively studied problems of X-ray astronomy is the disagreement of state-of-the art theory and observations for the intensity ratio of two Fe XVII…
Laser Spectroscopy of the yP states of Cr I
E. B. Norrgard, D. S. Barker, S. P. Eckel +5
Here we report measured and calculated values of decay rates of the 3d(D)4s4p(P)\ yP states of Cr I. The decay rates are measured usin…
Magic wavelengths of the Sr (--) intercombination transition near the -- transition
Grady Kestler, Khang Ton, Dmytro Filin +2
Predicting magic wavelengths accurately requires precise knowledge of electric-dipole matrix elements of nearby atomic transitions. As a result, measurements of magic wavelengths a…
Measurement of the tune-out wavelength for Cs at nm
Apichayaporn Ratkata, Philip D. Gregory, Andrew D. Innes +6
We perform a measurement of the tune-out wavelength, , between the , , and , , transitions fo…
Precision calculation of hyperfine constants for extracting nuclear moments of 229Th
S. G. Porsev, M. S. Safronova, M. G. Kozlov
Determination of nuclear moments for many nuclei relies on the computation of hyperfine constants, with theoretical uncertainties directly affecting the resulting uncertainties of…
Low-lying energy levels of ^{229}Th35+ and the electronic bridge process
S. G. Porsev, C. Cheung, M. S. Safronova
The nuclear transition between the ground and the low-energy isomeric state in the ^{229}Th nucleus is of interest due to its high sensitivity to a hypothetical temporal variation…
Scalable codes for precision calculations of properties of complex atomic systems
C. Cheung, M. S. Safronova, S. G. Porsev
High precision atomic data is indispensable for experiments involving studies of fundamental interactions, astrophysics, atomic clocks, plasma science, and others. We develop new p…
Role of triple excitations in calculating different properties of Ba+
S. G. Porsev, M. S. Safronova
We carried out calculations of the energies, hyperfine structure constants and electric-dipole transiton amplitudes for the low-lying states of Ba+ in the framework of the relativi…
Observation of an electric quadrupole transition in a negative ion: Experiment and Theory
C. W. Walter, S. E. Spielman, R. Ponce +4
The first direct experimental observation of an electric quadrupole (2) transition between bound states of an atomic negative ion has been made. The transition was obse…
Magic Wavelengths of the Yb Intercombination Transition
T. A. Zheng, Y. A. Yang, M. S. Safronova +4
We calculate and measure the magic wavelengths for the intercombination transition of the neutral ytterbium atom. The calculation is performed with th…
Predicting quasibound states of negative ions
M. S. Safronova, C. Cheung, M. G. Kozlov +3
We demonstrated the accurate prediction of a quasibound spectrum of a negative ion using a novel high-precision theoretical approach. We used La as a test case due to a recent…
Detection of missing low-lying atomic states in actinium
Ke Zhang, Dominik Studer, Felix Weber +10
Two lowest-energy odd-parity atomic levels of actinium, 7s^27p 2P^o_1/2, 7s^27p 2P^o_3/2, were observed via two-step resonant laser-ionization spectroscopy and their respective ene…
Calculation of higher-order corrections to the light shift of the -- clock transition in Cd
S. G. Porsev, M. S. Safronova
In the recent work [A.~Yamaguchi et. al, Phys. Rev. Lett. {\bf 123}, 113201 (2019)] Cd has been identified as an excellent candidate for a lattice clock. Here, we carried out compu…
Accurate prediction of clock transitions in a highly charged ion with complex electronic structure
C. Cheung, M. S. Safronova, S. G. Porsev +3
We have developed a broadly-applicable approach that drastically increases the ability to accurately predict properties of complex atoms. We applied it to the case of Ir, w…
High Resolution Photoexcitation Measurements Exacerbate the Long-Standing Fe XVII Oscillator Strength Problem
Steffen Kühn, Chintan Shah, José R. Crespo López-Urrutia +29
For more than 40 years, most astrophysical observations and laboratory studies of two key soft x-ray diagnostic transitions, and , in Fe XVII ions found oscillator…
Combining experiments and relativistic theory for establishing accurate radiative quantities in atoms: the lifetime of the P state in Ca
Ziv Meir, Mudit Sinhal, Marianna S. Safronova +1
We report a precise determination of the lifetime of the (4p)P state of Ca, ns, using a combination of measurements of the i…
Magic wavelength of the Ba clock transition
S. R. Chanu, V. P. W. Koh, K. J. Arnold +5
The zero crossing of the dynamic differential scalar polarizability of the clock transition in Ba has been determined to be THz. Toget…
Measurement of the state branching fractions in
M. Fan, C. A. Holliman, S. G. Porsev +2
We report a measurement of the radium ion's state branching fractions and improved theoretical calculations. With a single laser-cooled i…