Lewty Nicholas C, Chuah Boon Leng, Cazan Radu, Sahoo B K, Barrett M D
Centre for Quantum Technologies and Department of Physics, National University of Singapore, 3 Science Drive 2, 117543 Singapore.
Opt Express. 2012 Sep 10;20(19):21379-84. doi: 10.1364/OE.20.021379.
We present precision measurements of the hyperfine intervals in the 5D3/2 manifold of a single trapped Barium ion, ¹³⁷Ba⁺. Measurements of the hyperfine intervals are made between mF = 0 sublevels over a range of magnetic fields allowing us to interpolate to the zero field values with an accuracy below a few Hz, an improvement on previous measurements by three orders of magnitude. Our results, in conjunction with theoretical calculations, provide a 30-fold reduction in the uncertainty of the magnetic dipole (A) and electric quadrupole (B) hyperfine constants. In addition, we obtain the magnetic octupole constant (C) with an accuracy below 0.1Hz. This gives a subsequent determination of the nuclear magnetic octupole moment, Ω, with an uncertainty of 1% limited almost completely by the accuracy of theoretical calculations. This constitutes the first observation of the octupole moment in ¹³⁷Ba⁺ and the most accurately determined octupole moment to date.
我们展示了对单个囚禁钡离子¹³⁷Ba⁺的5D3/2多重态中超精细间隔的精确测量。在一系列磁场范围内对mF = 0子能级之间的超精细间隔进行了测量，这使我们能够以低于几赫兹的精度内插到零场值，比之前的测量提高了三个数量级。我们的结果与理论计算相结合，使磁偶极（A）和电四极（B）超精细常数的不确定性降低了30倍。此外，我们获得了精度低于0.1Hz的磁八极常数（C）。这随后确定了核磁八极矩Ω，其不确定性为1%，几乎完全受理论计算精度的限制。这是¹³⁷Ba⁺中八极矩的首次观测，也是迄今为止最精确测定的八极矩。
