Barium+ Octupole Measurement

We have performed precision measurements of the hyperfine intervals of the 5D3/2 and 5D5/2 manifolds in 137Ba+ to the accuracy of a few Hz.[1,2] These measurements provide a 30-fold reduction in the uncertainty in determining the nuclear magnetic dipole and electric quadrupole constants. In addition, we obtain the nuclear magnetic octupole moment to an accuracy of 1%. This was first observation of the octupole moment in 137Ba+ and the most accurately determined octupole moment to date. This measurement is limited only by theoretical uncertainties and provides a means to test atomic structure calculations.

Ion in high finesse cavity
References:
  1. [1] Lewty, N.C., Chuah, B.L., Cazan, R., Barrett, M.D., Spectroscopy on a single trapped 137Ba+ ion for nuclear magnetic octupole moment determination Optics Express 20(19), 21379 (2012).
  2. [2] Lewty, N.C., Chuah, B.L., Cazan, R., Barrett, M.D., Experimental determination of the nuclear magnetic octupole moment of 137Ba+ ion Physical Review A 88, 012518 (2013).