Magnetic trapping of metastable3P2atomic strontium

Abstract

We report the magnetic trapping of metastable ${}^3{P}_2$ atomic strontium. Atoms are cooled in a magneto-optical trap (MOT) operating on the dipole-allowed ${}^1{S}_0{-}^1{P}_1$ transition at 461 nm. Decay via ${}^1{\overrightarrow{P_1}}^1{\overrightarrow{D_2}}^3{P}_2$ continuously loads a magnetic trap formed by the quadrupole magnetic field of the MOT. Over ${10}^8$ atoms at a density of $8\times {10}^9{\mathrm{cm}}^{-3}$ and temperature of 1 mK are trapped. The atom temperature is significantly lower than what would be expected from the kinetic and potential energies of atoms as they are transferred from the MOT. This suggests the occurrence of thermalization and evaporative cooling in the magnetic trap.