A generalized probe sequence typical of trapped ion experiments using shelving is studied. Detection efficiency is analyzed for finite shelved state lifetimes and using multi-modal count distributions. Multi-modal distributions are more appropriate f
or measurements that use a small number of ions than the simple Poisson counting statistics usually considered and have a larger variance that may be significant in determining uncertainties and in making weighted fits. Optimal probe times and the resulting state detection efficiency and sensitivity are determined for arbitrary cooling rates, initial states and shelved state lifetimes, in terms of a probe coherence time {tau}p. A universal optimal probe time of tp ~ 0.43{tau}p is shown to give an almost optimal probe sensitivity for most systems.
A data acquisition system is described that is designed to stabilize cooling and probe rates to maximize detection sensitivity and minimize possible systematic errors due to correlations between drifting experimental conditions and varying drive para
meters. Experimental parameters that affect the Yb171 5D3/2 hyperfine state preparation and detection efficiency are characterized and optimized. A set of wait times for optimal sampling of the D3/2(F=2) lifetime is chosen and used to measure that lifetime with high statistical sensitivity. A systematic variation in this lifetime seems to be apparent. The source of the variation was not identified, but ion number and cooling rate appear to be ruled out. A net determination is made of tau=61.8ms+-(0.6)_stat+-(6.4)_sys which is significantly longer than other measurements of the same quantity. An alternate shelving scheme is proposed that would provide S-D state discrimination for Yb even isotopes as well as improved sensitivity for D state hyperfine discrimination in odd isotopes.
Atomic Parity Violation provides the rare opportunity of a low energy window into possible new fundamental processes at very high mass scales normally investigated at large high energy accelerators. Precise measurements on atomic systems are currentl
y the most sensitive probes of many kinds of new physics, and complement high energy experiments. Present atomic experiments are beginning to reach their limits of precision due to either sensitivity, systematics or atomic structure uncertainties. An experiment in a single trapped Barium ion can improve on all of these difficulties. This experiment uses methods to precisely manipulate and detect the spin state of a single ion in order to measure a parity induced splitting of the ground state magnetic sublevels in externally applied laser fields. The same methods can be used to provide precise measurements of more conventional atomic structure parameters.
We have employed the 12.6 GHz microwave transition resonance of a single trapped$^{171}$Yb+ ion to accurately measure the size and relative orientation of the magnetic and optical electric fields at the position of the ion in the trap. Accurate knowl
edge of these fields is required for precision experiments such as single ion PNC. As a proof of the principle we have measured the polarization dependent light-shift of the ground state hyperfine levels due to the 369 nm cooling laser to determine its electric field amplitude and polarization.
