Linewidth of single laser-cooled 24Mg+ ion in radiofrequency trap

摘要

A single Mg⁺ has been successfully trapped and cooled in a small radiofrequency trap. The ion was cooled by using the radiation from a single-frequency ring dye laser whose output was doubled in frequency with an NH4²H2PO4 temperature phasematched crystal; a power of about 22 μW or less was sufficient for all of the experiments. The ion temperature was estimated by a computer fit of the experimental resonance line profile; the resulting linewidth was compared to previously published Mg⁺ 3²P3/2 Hanle-effect linewidths. The result is a temperature of 5-5⁺¹⁵ mK, which is lower than that attained previously.