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Prospects of a Pb$^2+}$ ion clock



Kyle Beloy


We propose a high-performance atomic clock based on the 1.81 PHz transition between the ground and first-excited state of doubly ionized lead. Utilizing an even isotope of lead, both clock states have $I=J=F=0$, where $I$, $J$, and $F$ are the conventional quantum numbers specifying nuclear, electronic, and total angular momentum, respectively. The clock states are nondegenerate and completely immune to nonscalar perturbations, including first order Zeeman and electric quadrupole shifts. Additionally, the proposed clock is relatively insusceptible to other frequency shifts (blackbody radiation, second order Zeeman, Doppler), accommodates ''magic'' rf trapping, and is robust against relaxation and dephasing mechanisms that can otherwise limit clock stability. By driving the transition as a two-photon $E1$+$M1$ process, the accompanying probe Stark shift is appreciable yet manageable for practical Rabi frequencies.
Physical Review Letters


atomic clock, frequency standard, optical clock, optical frequency standard


Beloy, K. (2021), Prospects of a Pb$^{2+}$ ion clock, Physical Review Letters, [online], (Accessed July 23, 2024)


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Created June 29, 2021, Updated April 27, 2023