Electronic Bridge processes in $^{229}$Th-doped LiCAF and LiSAF
Abstract
Electronic bridge mechanisms driving the Th nuclear clock transition in the vacuum-ultraviolet-transparent crystals Th:LiCAF (LiCaAlF) and Th:LiSAF (LiSrAlF) are investigated theoretically. Due to doping-induced symmetry breaking within the host crystal, electronic defect states emerge around the thorium nucleus and can facilitate nuclear (de)excitation via laser-assisted electronic bridge mechanisms. We investigate spontaneous and laser-assisted electronic bridge schemes for different charge compensation mechanisms. While the calculated spontaneous electronic bridge rates are very small, laser-assisted electronic bridge schemes for nuclear (de)excitation turn out to be significantly more efficient than both spontaneous nuclear decay and direct laser excitation, offering promising prospects for the future clock operation.
Cite
@article{arxiv.2507.05070,
title = {Electronic Bridge processes in $^{229}$Th-doped LiCAF and LiSAF},
author = {Tobias Kirschbaum and Martin Pimon and Andreas Grüneis and Thorsten Schumm and Adriana Pálffy},
journal= {arXiv preprint arXiv:2507.05070},
year = {2025}
}