arXiv:physics/0312006 · Physical Review A
Hyperfine quenching of the metastable P0,23 states in divalent atoms
S. G. Porsev, Andrei Derevianko
Abstract
Hyperfine quenching rates of the lowest-energy metastable $^{3}P_{0}$ and $^{3}P_{2}$ states of Mg, Ca, Sr, and Yb atoms are computed. The calculations are carried out using ab initio relativistic many-body methods. The computed lifetimes may be useful for designing novel ultraprecise optical clocks and trapping experiments with the $^{3}P_{2}$ fermionic isotopes. The resulting natural widths of the $^{3}P_{0}\ensuremath{-}^{1}S_{0}$ clock transition are $0.44\phantom{\rule{0.3em}{0ex}}\text{mHz}$ for $^{25}\mathrm{Mg}$, $2.2\phantom{\rule{0.3em}{0ex}}\text{mHz}$ for $^{43}\mathrm{Ca}$, $7.6\phantom{\rule{0.3em}{0ex}}\text{mHz}$ for $^{87}\mathrm{Sr}$, $43.5\phantom{\rule{0.3em}{0ex}}\text{mHz}$ for $^{171}\mathrm{Yb}$, and $38.5\phantom{\rule{0.3em}{0ex}}\text{mHz}$ for $^{173}\mathrm{Yb}$. Compared to the bosonic isotopes, the lifetime of the $^{3}P_{2}$ states in fermionic isotopes is noticeably shortened by the hyperfine quenching but still remains long enough for trapping experiments.