New prospects for precision spectroscopy on ultra-cold magnesium atoms

Latest results in high precision spectroscopy, where resolutions as low as 290 Hz have been obtained with the Ramsey-Borde interferometer tuned to the 3¹S₀ → 3³P₁ intercombination line at 457 nm are reported. The potential short- term stability inferred from the signal is 8×10^-14 in 1 s comparable to the stability of present state-of-the-art microwave frequency standards. The residual atomic motion of the atoms, which is due to the Doppler temperature of 2 mK., is identified as a main limiting factor for the achievable resolution. The prospects for magnesium, the current status of the experimental implementation and theoretical studies of the cooling mechanisms are presented.