Quadrupole shifts for theYb+171ion clocks: Experiments versus theories
Physical Review A. Atomic, Molecular, and Optical Physics
Quadrupole shifts for three prominent clock transitions, [4f^14 6s] ^2S_1/2→ [4f^14 5d] ^2D_3/2, [4f^14 6s] ^2S_1/2→ [4f^14 5d] ^2D_5/2 and [4f^14 6s] ^2S_1/2→ [4f^13 6s^2] ^2F_7/2, in the Yb^+ ion are investigated by calculating the quadrupole moments (Θs) of the 5d_3/2,5/2 and 4f_7/2 states using the relativistic coupled-cluster (RCC) methods. We find an order difference in the Θ value of the 4f_7/2 state between our calculation and the experimental result, but our result concur with the
... calculations that are carried out using different many-body methods than ours. However, our Θ value of the 5d_3/2 state is in good agreement with the available experimental result and becomes more precise till date to estimate the the quadrupole shift of the [4f^14 6s] ^2S_1/2→ [4f^14 5d] ^2D_3/2 clock transition more accurately. To justify the accuracies in our calculations, we evaluate the hyperfine structure constants of the 6s_1/2, 5d_3/2,5/2 and 4f_7/2,5/2 states of ^171Yb^+ ion using the same RCC methods and compare the results with their experimental values. We also determine the lifetime of the 5d_3/2 state to eradicate the scepticism on the earlier measured value as claimed by a recent experiment.