Simultaneous Magneto-Optical Trapping of a Boson-Fermion Mixture of Metastable Helium Atoms

We simultaneously confine fermionic metastable ${}^3\mathrm{H}\mathrm{e}$ atoms and bosonic metastable ${}^4\mathrm{H}\mathrm{e}$ atoms in a magneto-optical trap. The trapped clouds, containing up to $1.5\times {10}^8$ atoms of each isotope, are characterized by measuring ions and metastable helium atoms escaping from the trap. Optical pumping of ${}^3\mathrm{H}\mathrm{e}$ atoms to a nontrapped hyperfine state is investigated and it is shown that large atom numbers can be confined without additional repumping lasers. Unique possibilities for quantum degeneracy experiments with mixtures of spin-polarized metastable ${}^3\mathrm{H}\mathrm{e}$ and ${}^4\mathrm{H}\mathrm{e}$ atoms are indicated.