Realization of a Magneto-Optical Trap for Cadmium Atoms*

We report the confinement of cadmium atoms in a vapor cell magneto-optical trap (MOT). Using the closed $^{1}$S$_{0}-^{1}$P$_{1}$ transition ($\lambda $=229 nm, $\gamma $=2$\pi $*90.9 MHz), we are able to trap neutral cadmium atoms and examine the dependence of loss mechanisms, atomic density, and atom number on trapping parameters. This represents the trapping of a new atomic species and the shortest wavelength MOT produced to date. We anticipate that cold Cd atoms will be interesting for future studies in at least two directions: First, the $^{1}$S$_{0}-^{3}$P intercombination lines ($\lambda $=325 nm) could be useful for optical cooling to very low temperatures ($^{1}$S$_{0}-^{3}$P$_{1})$ and for high resolution optical spectroscopy ($^{1}$S$_{0}-^{3}$P$_{0})$. Second, combining cold Cd atoms with individual laser-cooled Cd$^{+}$ ions in a nearby ion trap may allow for studies of cold ion/neutral interactions such as charge-exchange, the transport of a charged ``hole'' through a gas, and perhaps the transfer of coherence from hyperfine states in the ion to pure nuclear spins in the neutral gas.