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A: Fachverband Atomphysik
A 20: Precision spectroscopy of atoms and ions III
A 20.4: Vortrag
Mittwoch, 11. März 2020, 15:00–15:15, f303
Electronic Bridge in 229Th doped CaF2 — Brenden Nickerson1, Martin Pimon2, •Pavlo Bilous1, Thorsten Schumm2, and Adriana Pálffy1 — 1Max Planck Institute for Nuclear Physics, Heidelberg — 2Technical University of Vienna, Austria
The lowest known nuclear transition of only 8 eV in 229Th could serve as basis for a novel nuclear clock. However, direct photoexcitation of this nuclear state has so far remained elusive. One promising approach is to use thorium-doped VUV-transparent crystals which can host a large number of 229Th nuclei [1,2].
Here an alternative method of excitation using for the first time the concept of electronic bridge (EB) in the crystal is investigated theoretically. EB makes use of the electronic shell as an intermediate stepping stone for the transfer of energy between laser photons and nuclei [3]. In VUV-transparent crystals this process is facilitated by defects, i.e., states appearing in the band gap, caused by the Th doping. In the context of current crystal experiments the EB process promises excitation rates far above direct photoexcitation with current technology. Such results contribute to the development of a nuclear frequency standard based on 229mTh.
[1] Stellmer, Schreitl, & Schumm, Sci. Rep. 5, 15580 (2015)
[2] Dessovic et al., J. Phys.:Condens. Matter 26, 105402 (2014)
[3] Porsev & Flambaum, Phys. Rev. A 81, 032504 (2010)