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

Abstract

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 NH 4 2 H 2 PO 4 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 + 3 2 P 3/2 Hanle-effect linewidths. The result is a temperature of 5 -5 +15 mK, which is lower than that attained previously.