Magneto-optical trapping of mercury at high phase space density

TL;DR

This paper demonstrates a magneto-optical trap for mercury atoms, achieving high phase space density and cooling of multiple isotopes, which is promising for future quantum experiments.

Contribution

It reports the first high phase space density magneto-optical trap of mercury atoms on the intercombination line, including all stable isotopes and sub-Doppler cooling.

Findings

Trapped 50 million Hg-202 atoms.

Achieved phase space density of 10^-6.

Observed sub-Doppler cooling in fermionic isotopes.

Abstract

We present a realization of a magneto-optical trap of mercury atoms on the 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 Hg-202 is 50 million 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^-6, which consitutes a promising starting condition for dipole trap loading and evaporative cooling.