Kilohertz-resolution spectroscopy of the 2S1/2-2F7/2 electric octupole transition in a single 171Yb+ ion -: art. no. 052501

Spectroscopy has been performed on the S-2(1/2)(F=0, m(F)=0)-F-2(7/2)(F=3,m(F)=0) electric octupole transition in Yb-171(+) with kilohertz resolution. A quantum jump rate of more than one per second has been achieved, a factor of 100 improvement on previous work. Spectra including the sidebands at the trap secular frequency show the ion to be in the Lambe-Dicke regime and hence the Doppler effect has been eliminated to first order. The dynamic Stark shift is a significant perturbation to the frequency because of the high intensity required to drive the octupole transition. It has been measured as 42(-10)(+12) muHz W-1 m(2) and with further reduction in the probe laser linewidth, it should be possible to reduce the relative uncertainty in this shift to the parts in 10(18) level. The transition is free from the Zeeman effect to first order and has a measured second-order shift of 1.9(3) mHz (muT)(-2). It should be possible to reduce the relative uncertainty in this shift to below the part in 10(18) level. The electric quadrupole shift may be the limiting systematic effect, but cannot yet be observed with the current resolution on the transition.