Magneto-optical trapping of mercury at high phase-space density

Abstract

We present a realization of a magneto-optical trap of mercury atoms on the $^{1}S_{0}\ensuremath{\rightarrow}^{3}P_{1}$ intercombination line. We report on trapping of all stable mercury isotopes. We characterize the effect of laser detuning, laser intensity, and gradient field on the trapping performance of our system. The atom number for the most abundant isotope $^{202}\mathrm{Hg}$ is $5\ifmmode\times\else\texttimes\fi{}{10}^{7}$ atoms. Moreover, we study the difference in cooling processes for bosonic and fermionic isotopes. We observe agreement with the Doppler cooling theory for the bosonic species and show sub-Doppler cooling for the fermionic species. We reach a phase-space density of a few parts in ${10}^{\ensuremath{-}7}$, which constitutes a promising starting condition for dipole trap loading and evaporative cooling.