Abstract

We have performed a study of quantum jumps in single magnesium ions held in a Penning trap. This system is unusual in that quantum jumps may be observed using only a single laser frequency which serves to laser cool the ion (providing fluorescence for detection), shelve the ion in a metastable state (via, an off-resonant Raman transition) and also to repump the ion from the metastable state back into the cooling cycle (again via a Raman transition). Single ²⁴Mg⁺ ions have been studied in a Penning trap before [1,2] but we have predicted and now observed a number of interesting effects that occur only in ²⁵Mg⁺. We have also trapped single ions of ²⁶Mg⁺ and confirmed that their quantum jump behaviour is similar to that of ²⁴Mg⁺ as expected. The novel features in the behaviour of “Mg'⁴ are due to the presence of hyperfine structure in tiffs ion.

© 2000 IEEE