Quantum treatment of twostage subDoppler laser cooling of magnesium atoms
Abstract
The problem of deep laser cooling of $^{24}$Mg atoms is theoretically studied. We propose twostage subDoppler cooling strategy using electrodipole transition $3^3P_2$$\to$$3^3D_3$ ($\lambda$=383.9 nm). The first stage implies exploiting magnetooptical trap with $\sigma^+$ and $\sigma^$ light beams, while the second one uses a lin$\perp$lin molasses. We focus on achieving large number of ultracold atoms (T$_{eff}$ < 10 $\mu$K) in a cold atomic cloud. The calculations have been done out of many widely used approximations and based on quantum treatment with taking full account of recoil effect. Steadystate average kinetic energies and linear momentum distributions of cold atoms are analysed for various lightfield intensities and frequency detunings. The results of conducted quantum analysis have revealed noticeable differences from results of semiclassical approach based on the FokkerPlanck equation. At certain conditions the second cooling stage can provide sufficiently lower kinetic energies of atomic cloud as well as increased fraction of ultracold atoms than the first one. We hope that the obtained results can assist overcoming current experimental problems in deep cooling of $^{24}$Mg atoms by means of laser fields. Cold magnesium atoms, being cooled in large number down to several microkelvins, have certain interest, for example, in quantum metrology.
 Publication:

arXiv eprints
 Pub Date:
 August 2015
 DOI:
 10.48550/arXiv.1508.03694
 arXiv:
 arXiv:1508.03694
 Bibcode:
 2015arXiv150803694B
 Keywords:

 Physics  Atomic Physics;
 Condensed Matter  Quantum Gases;
 Quantum Physics
 EPrint:
 11 pages, 7 figures, 1 table