Magneto-optical trapping of rubidium atoms: isotope separation and cold collisions

We report measurements of collisional rate constants for cold Rb atoms held in a magneto-optical trap. $^{85}\mathrm{Rb}$ and $^{87}\mathrm{Rb}$ display significantly different behavior. At low trap laser intensities, atoms which undergo a hyperfine-changing collision gain sufficient velocity to escape the trap. Since the hyperfine splittings are quite different for the isotopes, the loss rates display a large isotopic dependence in this regime. At higher trap laser intensities, where trap loss is due to inelastic collisions involving excited atoms, a dramatic and unexpected isotopic dependence is seen. Under identical conditions, the loss rate for $^{85}\mathrm{Rb}$ is 3.3 times that of $^{87}\mathrm{Rb}$ .We report measurements of collisional rate constants for cold Rb atoms held in a magneto-optical trap. $^{85}\mathrm{Rb}$ and $^{87}\mathrm{Rb}$ display significantly different behavior. At low trap laser intensities, atoms which undergo a hyperfine-changing collision gain sufficient velocity to escape the trap. Since the hyperfine splittings are quite different for the isotopes, the loss rates display a large isotopic dependence in this regime. At higher trap laser intensities, where trap loss is due to inelastic collisions involving excited atoms, a dramatic and unexpected isotopic dependence is seen. Under identical conditions, the loss rate for $^{85}\mathrm{Rb}$ is 3.3 times that of $^{87}\mathrm{Rb}$.

Physical Review LettersAug 10, 1992122 citations

Spectroscopy of rubidium atoms in a magneto-optical trap

Thomas Lindvall, Juha Toivonen, Ilkka Juhani Tittonen +2 more

Jan 1, 19990 citations

A Study of Rubidium Atoms in a Magneto-Optical Trap

A. Pietiläinen, H. Ludvigsen, Hannu Talvitie +1 more

Jan 1, 19950 citations

Investigation of cold collision in a two isotope magneto-optical trap for Krypton atoms

S. Singh, Vibhuti Bhushan Tiwari, Y. B. Kale +2 more

Abstract We report simultaneous cooling and trapping of metastable 84 Kr ( 84 Kr*) and metastable 86 Kr ( 86 Kr*) atoms by overlapping the cooling laser beams for these different isotopes in the same region of a magneto-optical trap (MOT). Approximately 2 × 10 5 atoms of each isotope were trapped in this two isotope-MOT (TIMOT). We have investigated the heteronuclear collision trap loss rates for each isotope due to the presence of cold atoms of other isotope using the TIMOT loading curves. The two body heteronuclear loss rate coefficient (i.e. for the loss of 84 Kr* due to presence of 86 Kr*) and the reciprocal loss rate coefficient (i.e. for the loss of 86 Kr* due to presence of 84 Kr*) are measured to be (8.7 ± 0.8) × 10 −10 cm 3 s −1 and (8.8 ± 0.8) × 10 −10 cm 3 s −1 respectively for laser beam intensity values of 21 mW cm −2 (for cooling of 84 Kr*) and 64 mW cm −2 (for cooling of 86 Kr*). The dependence of heteronuclear cold collision loss rate on cooling laser beams intensity has also been studied and compared with homonuclear cold collision loss rate.Abstract We report simultaneous cooling and trapping of metastable 84 Kr ( 84 Kr*) and metastable 86 Kr ( 86 Kr*) atoms by overlapping the cooling laser beams for these different isotopes in the same region of a magneto-optical trap (MOT). Approximately 2 × 10 5 atoms of each isotope were trapped in this two isotope-MOT (TIMOT). We have investigated the heteronuclear collision trap loss rates for each isotope due to the presence of cold atoms of other isotope using the TIMOT loading curves. The two body heteronuclear loss rate coefficient (i.e. for the loss of 84 Kr* due to presence of 86 Kr*) and the reciprocal loss rate coefficient (i.e. for the loss of 86 Kr* due to presence of 84 Kr*) are measured to be (8.7 ± 0.8) × 10 −10 cm 3 s −1 and (8.8 ± 0.8) × 10 −10 cm 3 s −1 respectively for laser beam intensity values of 21 mW cm −2 (for cooling of 84 Kr*) and 64 mW cm −2 (for cooling of 86 Kr*). The dependence of heteronuclear cold collision loss rate on cooling laser beams intensity has also been studied and compared with homonuclear cold collision loss rate.

Journal of Physics B Atomic Molecular and Optical PhysicsJul 23, 20152 citations

Measurement of the lifetime of rubidium atoms in a dark magneto-optical trap

O. I. Permyakova, A. V. Yakovlev, P. L. Chapovsky

The lifetimes of rubidium atoms in a dark magneto-optical trap are measured at different populations of the 'bright' and 'dark' hyperfine states of captured atoms. It is found that the lifetime of atoms in the trap decreases if they spend more time in the bright state. A simple explanation of this effect is proposed which is based on the increase in the transport cross section for collisions of thermal rubidium atoms surrounding the trap with cold rubidium atoms upon their electronic excitation.The lifetimes of rubidium atoms in a dark magneto-optical trap are measured at different populations of the 'bright' and 'dark' hyperfine states of captured atoms. It is found that the lifetime of atoms in the trap decreases if they spend more time in the bright state. A simple explanation of this effect is proposed which is based on the increase in the transport cross section for collisions of thermal rubidium atoms surrounding the trap with cold rubidium atoms upon their electronic excitation.

Quantum ElectronicsSep 30, 20085 citations

We report measurements of collisional rate constants for cold Rb atoms held in a magneto-optical trap.

^{85}\mathrm{Rb}

and

^{87}\mathrm{Rb}

display significantly different behavior. At low trap laser intensities, atoms which undergo a hyperfine-changing collision gain sufficient velocity to escape the trap. Since the hyperfine splittings are quite different for the isotopes, the loss rates display a large isotopic dependence in this regime. At higher trap laser intensities, where trap loss is due to inelastic collisions involving excited atoms, a dramatic and unexpected isotopic dependence is seen. Under identical conditions, the loss rate for

^{85}\mathrm{Rb}

is 3.3 times that of

^{87}\mathrm{Rb}