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The A(1)Σu(+) - X(1)Σg(+) UV spectrum of Mg2 has been investigated with high resolution Fourier-transform spectroscopy. Mg2 vapor was created in a heat pipe. Various spectroscopic methods have been employed, such as conventional absorption spectroscopy with light from a broad band lamp and laser-induced fluorescence. The high resolution of the Fourier-transform spectrometer, together with computer aided evaluation methods of the spectra, yields precise transition frequencies. The new data and data available from earlier investigations are applied in direct potential fits of lower and upper electronic states. Various representations of potential energy curves for the ground state X(1)Σg(+) have been employed and their benefits in terms of smallest number of parameters are discussed. Scattering lengths are derived for the homonuclear isotopologues and compared with previous results.

We optically excite the electronic state 3s3p 3 P0 in 24 Mg atoms, laser-cooled and trapped in a magic-wavelength lattice. An applied magnetic field enhances the coupling of the light to the otherwise strictly forbidden transition. We determine the magic wavelength, the quadratic magnetic Zeeman shift and the transition frequency to be 468.463(207) nm, −206.6(2.0) MHz/T 2 and 655 058 646 691(101) kHz, respectively. These are compared with theoretical predictions and results from complementary experiments. We also developed a high-precision relativistic structure model for magnesium, give an improved theoretical value for the blackbody radiation shift and discuss a clock based on bosonic magnesium.

We load 10 5 magnesium atoms in a dipole trap from a millikelvin-hot magneto-optical trap (MOT) using a continuous-loading scheme. Light-assisted two-body processes limit the maximum achievable density in a MOT, resulting in a reduced transfer efficiency into a dipole trap when using the conventional sequential scheme. It is overcome in a continuous-loading scheme where a loss channel is opened in the MOT. This allows the accumulation of atoms in the dipole trap over the trap lifetime, determined by collisions with the background gas. This results in a significantly higher number of trapped atoms even at a lower steady-state peak density in the MOT.