Journal Article

• Nörtershäuser W, Ullmann J et al. The hyperfine puzzle of strong-field bound-state QED, Hyperfine Interactions, 240: 51 (2019)

• Hannen V, Vollbrecht J et al. Lifetimes and g-factors of the HFS states in H-like and Li-like bismuth, Journal of Physics B: Atomic, Molecular and Optical Physics, 52(8): 085003 (2019)

• Sánchez R, Lochmann M et al. Laser spectroscopy measurement of the 2s-hyperfine splitting in lithium-like bismuth, Journal of Physics B - Atomic Molecular and Optical Physics, 50(8): 085004 (2017)

• Ullmann J, Andelkovic Z et al. High precision hyperfine measurements in Bismuth challenge bound-state strong-field QED, Nature Communications, 8: 15484 (2017)

• Sánchez R, Ullmann J et al. Hyperfine transition in ²⁰⁹Bi⁸⁰⁺—one step forward, Physica Scripta, T166: 014021 (2015)
  

• Ullmann J, Andelkovic Z et al. An improved value for the hyperfine splitting of hydrogen-like ²⁰⁹Bi⁸²⁺, Journal of Physics B: Atomic, Molecular and Optical Physics, 48(14): 144022 (2015)

• Lochmann M, Joehren R et al. Observation of the hyperfine transition in lithium-like bismuth ²⁰⁹Bi⁸⁰⁺ : Towards a test of QED in strong magnetic fields, Physical Review A, 90(3): 030501 (2014)

Conference Paper

• Vollbrecht J, Andelkovic Z et al. Laser spectroscopy of the ground-state hyperfine structure in H-like and Li-like bismuth, 17th International Conference on the Physics of Highly Charged Ions, Journal of Physics: Conference Series, 583: 012002 (2015)

• Nörtershäuser W, Lochmann M et al. First observation of the ground-state hyperfine transition in ²⁰⁹Bi⁸⁰⁺, 16th International Conference on the Physics of Highly Charged Ions (HCI), Physica Scriptura, T156: 014016 (2013)

Link to the main page of SPECTRAP at GSI, Germany.

Journal Article

• Schmidt S, Murböck T et al. Sympathetic cooling in two-species ion crystals in a Penning trap, Journal of Modern Optics, 65(5-6): 538-548 (2017)

• Murböck T, Schmidt S et al. Rapid crystallization of externally produced ions in a Penning trap, Physical Review A, 94(4): 043410 (2016) 

• Vogel M, Andelkovic Z et al. Penning-trap experiments for spectroscopy of highly-charged ions at HITRAP., Physica Scripta, T166: 014066 (2015)

• Andelkovic Z, Cazan R et al. Laser cooling of externally produced Mg ions in a Penning trap for sympathetic cooling of highly charged ions, PHYSICAL REVIEW A, 87(3): 033423 (2013)

Conference Paper

• Murböck T, Albrecht S et al. SpecTrap: precision spectroscopy of highly charged ions-status and prospects, 16th International Conference on the Physics of Highly Charged Ions (HCI), Physica Scripta, T156: 014096 (2013)

• Andjelkovic Z, Barth W et al. HITRAP-a facility for experiments on heavy highly charged ions and on antiprotons, Journal of Physics: Conference Series, 194(14): 142007 (2009)

• Kluge H-J, Beier T et al. HITRAP: A facility at GSI for highly charged ions, Symposium in Honor of Ingvar Lindgrens 75th Birthday. In: Salomonson S, Lindroth E (eds.) Advances in Quantum Chemistry, Current Trends in Atomic Physics, 53: 83-98. ISSN: 0065-3276 (2008)

• Winters DFA, Vogel M et al. Laser spectroscopy of hyperfine structure in highly charged ions: a test of QED at high fields, International Workshop on Precision Physics of Simple Atomic Systems, Canadian Hournal of Physics, 85(5): 403-408 (2007)

Link to the main page of Ion Traps at National Physical Laboratory (NPL), UK

Journal Article

• Brownnutt M, Letchumanan V et al. Controlled photoionization loading of Sr-88(+) for precision ion-trap experiments, APPLIED PHYSICS B-LASERS AND OPTICS, 87:411-415 (2007)

• Brownnutt M, Wilpers G, et al. Monolithic microfabricated ion trap chip design for scaleable quantum processors, NEW JOURNAL OF PHYSICS, 8(10):232 (2006)