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Measurement of the 199Hg+ 5d96s2 2d5/2 Electric Quadrupole Moment and a Constraint on the Quadrupole Shift



Windell Oskay, Wayne M. Itano, James C. Bergquist


The electric quadrupole moment of the 199Hg+ 5d96s22d5/2 state is measured to be (D, 5/2) = -2.98(8) × 10-40 C m2. The value was determined by measuring the frequency of the 199Hg+ 5d106s2S1/2 – 5d96s22d5/2 optical clock transition for different applied electric field gradients. An isolated, mechanically stable optical cavity provides a frequency reference for the measurement. We compare the results with theoretical calculations and discuss the implications for the accuracy of an atomic clock based upon this transition. We now expect that the frequency shift caused by the interaction of the quadrupole moment with stray electric-field gradients will not be limit the accuracy of the Hg+ optical clock at the 10-18 level.
Physical Review Letters


ion, laser, optical standard


Oskay, W. , Itano, W. and Bergquist, J. (2005), Measurement of the <sup>199</sup>Hg<sup>+</sup> 5d<sup>9</sup>6s<sup>2</sup> <sup>2<sub></sub>d5/2</sup> Electric Quadrupole Moment and a Constraint on the Quadrupole Shift, Physical Review Letters, [online], (Accessed June 23, 2024)


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Created April 29, 2005, Updated January 27, 2020