Publications

  1. Landé g factor measurement of 48Ti+ using simultaneous co-magnetometry and quantum logic spectroscopy, Till Rehmert, Maximilian J. Zawierucha, Kai Dietze, Piet O. Schmidt, Fabian Wolf, Sergey Porsev, Dmytro Filin, Charles Cheung, Marianna S. Safronova, arXiv:2508.15488 (2025). PDF
  2. Multimessenger Astronomy Beyond the Standard Model: New Window from Quantum Sensors, Jason Arakawa, Muhammad H. Zaheer, Volodymyr Takhistov, Marianna S. Safronova, Joshua Eby and Charles Cheung, arXiv:2502.0871 (2025). PDF
  3. Portal for High-Precision Atomic Data and Computation, Amani Kiruga, Charles Cheung, Dmytro Filin, Marianna S. Safronova, Parinaz Barakhshan, Akshay Bhosale, Rudolf Eigenmann, Vipul Badhan, Bindiya Arora, arXiv:2506.08170 (2025). PDF
  4. Lifetimes of bound excited states of the lanthanum negative ion and implications for laser cooling: Experiment and Theory, C. W. Walter, F. E. Vassallo, J. Karls, D. Leimbach, D. Hanstorp, J. E. Navarro Navarrete, O. H. Lundgren, M. K. Kristiansson, M. Björkhage, R. D. Thomas, H. Zettergren, H. T. Schmidt, C. Cheung, M. S. Safronova, and N. D. Gibson, submitted to PRA (2025).
  5. Polarizabilities of low-lying states of silver, S. G. Porsev, D. Filin, C. Cheung, and M. S. Safronova, Phys. Rev. A 111, 062809 (2025). PDF
  6. A neural-network-based Python package for performing large-scale atomic CI using pCI and other high-performance atomic codes, Pavlo Bilous, Charles Cheung, Marianna S. Safronova, Comput. Phys. Commun. 315, 109731 (2025). PDF
  7. Excited-State Magnetic Properties of Carbon-like calcium Ca14+, Lukas J. Spieß, Shuying Chen, Alexander Wilzewski, Malte Wehrheim, Jan Gilles, Andrey Surzhykov, Erik Benkler, Melina Filzinger, Martin Steinel, Nils Huntemann, Charles Cheung, Sergey G. Porsev, Andrey I. Bondarev, Marianna S. Safronova, José R. Crespo López-Urrutia, and Piet O. Schmidt, Phys. Rev. Lett. 135, 043002 (2025). PDF
  8. Finding the ultra-narrow 3P2 → 3P0 electric quadrupole transition in Ni12+ ion for an optical clock, Charles Cheung, Sergey G. Porsev, Dmytro Filin, Marianna S. Safronova, Malte Wehrheim, Lukas J. Spieß, Shuying Chen, Alexander Wilzewski, José R. Crespo López-Urrutia, and Piet O. Schmidt, Phys. Rev. Lett. 135, 093002 (2025). PDF
  9. pCI: a parallel configuration interaction software package for high-precision atomic structure calculations, Charles Cheung, Mikhail G. Kozlov, Sergey G. Porsev, Marianna S. Safronova, Ilya I. Tupitsyn, and Andrey I. Bonderev, Comput. Phys. Commun. 308, 109463 (2025). PDF
  10. Pr10+ as a candidate for a high-accuracy optical clock for tests of fundamental physics, S. G. Porsev, C. Cheung, M. S. Safronova, H. Bekker, N.-H. Rehbehn, J. R. Crespo López-Urrutia, and S. M. Brewer, Phys. Rev. A 110, 042823 (2024). PDF
  11. A neural network approach to running high-precision atomic computations, Pavlo Bilous, Charles Cheung, and Marianna S. Safronova, Phys. Rev. A 110, 042818 (2024). PDF
  12. Prospects of a thousand-ion Sn2+ Coulomb-crystal clock with sub-10-19 inaccuracy, David R. Leibrandt, Sergey G. Porsev, Charles Cheung, and Marianna S. Safronova, Nature Communications 15, 5663 (2024). PDF
  13. High-Precision Transition Energy Measurements of Neon-like Fe XVII Ions, Chintan Shah, Moto Togawa, Marc Botz, Jonas Danisch, Joschka J. Goes, Sonja Bernitt, Marleen Maxton, Kai Köbnick, Jen Buck, Jörn Seltmann, Moritz Hoesch, Ming Feng Gu, F. Scott Porter, Thomas Pfeifer, Maurice A. Leutenegger, Charles Cheung, Marianna S. Safronova, José R. Crespo López-Urrutia, ApJ 969 52 (2024). PDF
  14. Lifetime-Limited Linewidth Measurements of the 3C and 3D Soft X-ray Transitions in Ni XIX, Chintan Shah, Steffen Kühn, Sonja Bernitt, René Steinbrügge, Moto Togawa, Lukas Berger, Jens Buck, Moritz Hoesch, Jörn Seltmann, Mikhail G. Kozlov, Sergey G. Porsev, Ming Feng Gu, F. Scott Porter, Thomas Pfeifer, Maurice A. Leutenegger, Charles Cheung, Marianna S. Safronova, and José R. Crespo López-Urrutia, Phys. Rev. A 109, 063108 (2024). PDF
  15. State-Insensitive Trapping of Alkaline-Earth Atoms in a Nanofiber-Based Optical Dipole Trap, K. Ton, G. Kestler, D. Filin, C. Cheung, P. Schneeweiss, T. Hoinkes, J. Volz, M. S. Safronova, A. Rauschenbeutel, and J. T. Barreiro, PRX Quantum 4, 040308 (2023). PDF
  16. Calculations of multipole transitions in Sn II for kilonova analysis, Andrey I. Bondarev, James Gillanders, Charles Cheung, Marianna S. Safronova, and Stephan Fritzsche, Eur. Phys. J. D 77, 126 (2023). PDF
  17. Optical telecommunications-band clock based on neutral titanium atoms, Scott Eustice, Dmytro Filin, Jackson Schrott, Sergey Porsev, Charles Cheung, Diego Novoa, Dan M. Stamper-Kurn, and Marianna S. Safronova, Phys. Rev. A 107, L051102 (2023). PDF
  18. Calculation of energies and hyperfine structure constants of 233U+ and 233U, S. G. Porsev, C. Cheung, and M. S. Safronova, Phys. Rev. A 106, 042810 (2022). PDF
  19. New Measurement Resolves Key Astrophysical Fe XVII Oscillator Strength Problem, Steffen Kuhn, Charles Cheung, Natalia S. Oreshkina, René Steinbrügge, Moto Togawa, Sonja Bernitt, Lukas Berger, Jens Buck, Moritz Hoesch, Jörn Seltmann, Florian Trinter, Christoph H. Keitel, Mikhail G. Kozlov, Sergey G. Porsev, Ming Feng Gu, F. Scott Porter, Thomas Pfeifer, Maurice A. Leutenegger, Zoltán Harman, Marianna S. Safronova, José R. Crespo López-Urrutia, and Chintan Shah, Phys. Rev. Lett. 129, 245001 (2022). PDF
  20. Laser spectroscopy of the y 7PJo states of Cr I, E. B. Norrgard, D. S. Barker, S. P. Eckel, S. G. Porsev, C. Cheung, M. G. Kozlov, I. I. Tupitsyn, and M. S. Safronova, Phys. Rev. A 105, 032812 (2022). PDF
  21. Low-lying energy levels of 229Th35+ and the electronic bridge process, S. G. Porsev, C. Cheung and M. S. Safronova, Quantum Science and Technology 6, 034014 (2021). PDF
  22. Development of a relativistic atomic theory for accurate treatment of complex correlations, Charles Cheung, Ph.D. Thesis (2021). PDF
  23. Scalable Codes for Precision Calculations of Properties of Complex Atomic Systems, Charles Cheung, Marianna Safronova and Sergey Porsev, Symmetry 13(4), 621 (2021). PDF
  24. Observation of an electric quadrupole transition in a negative ion: Experiment and Theory, C.W. Walter, S. E. Spielman, R. Ponce, N. D. Gibson, J. N. Yukich, C. Cheung, M. S. Safronova, Phys. Rev. Lett. 126, 083001 (2021). PDF
  25. Predicting quasibound states of negative ions: La- as a test case, M. S. Safronova, C. Cheung, M. G. Kozlov, S.E. Spielman, N. D. Gibson, C. W. Walter, Phys. Rev. A 103, 022819 (2021). PDF
  26. Detection of the Lowest-Lying Odd-Parity Atomic Levels in Actinium, Ke Zhang, Dominik Studer, Felix Weber, Vadim M. Gadelshin, Nina Kneip, Sebastian Raeder, Dmitry Budker, Klaus Wendt, Tom Kieck, Sergey G. Porsev, Charles Cheung, Marianna S. Safronova, Mikhail G. Kozlov, Phys. Rev. Lett. 125, 073001 (2020). PDF
  27. Optical clocks based on the Cf15+ and Cf17+ ions, S. G. Porsev, U. I. Safronova, M. S. Safronova, P. O. Schmidt, A. I. Bondarev, M. G. Kozlov, I. I. Tupitsyn, C. Cheung, Phys. Rev. A 102, 012802 (2020). PDF
  28. High-resolution photo-excitation measurements exacerbate the long-standing Fe XVII emission problem, Steffen Kuhn, Chintan Shah, José R. Crespo López-Urrutia, Keisuke Fujii, René Steinbrügge, Jakob Stierhof, Moto Togawa, Zoltán Harman, Natalia S.Oreshkina, Charles Cheung, Mikhail G. Kozlov, Sergey G. Porsev, Marianna S. Safronova, Julian C. Berengut, Michael Rosner, Matthias Bissinger, Ralf Ballhausen, Natalie Hell, SungNam Park, Moses Chung, Moritz Hoesch, Jörn Seltmann, Andrey S. Surzhykov, Vladimir A. Yerokhin, Jörn Wilms, F. Scott Porter, Thomas Stöhlker, Christoph H. Keitel, Thomas Pfeifer, Gregory V. Brown, Maurice A. Leutenegger, Sven Bernitt, Phys. Rev. Lett. 124, 225001 (2020). PDF
  29. Accurate prediction of clock transitions in a highly charged ion with complex electronic structure, C. Cheung, M. S. Safronova, S. G. Porsev, M. G. Kozlov, I. I. Tupitsyn, A. I. Bondarev, Phys. Rev. Lett. 124, 163001 (2020). PDF