The ac Stark shift produced by nonresonant radiation creates a potential minimum for a ground state molecule at the position where the laser intensity is maximum. The gradient of this potential exerts a force on the molecule. We experimentally observe this force when a beam of ${\mathrm{CS}}_{2}$ molecules is redirected by sending it through the intensity gradient near the focus of a laser beam. We trace the direction of the molecules in the molecular beam, showing that the molecules that pass near the center of the high intensity laser beam will focus.The ac Stark shift produced by nonresonant radiation creates a potential minimum for a ground state molecule at the position where the laser intensity is maximum. The gradient of this potential exerts a force on the molecule. We experimentally observe this force when a beam of ${\mathrm{CS}}_{2}$ molecules is redirected by sending it through the intensity gradient near the focus of a laser beam. We trace the direction of the molecules in the molecular beam, showing that the molecules that pass near the center of the high intensity laser beam will focus.

Physical Review LettersOct 13, 1997198 citations

Manipulating Neutral Atoms and Molecules by Strong Non-Resonant Laser Fields

Mark Y. Vilensky

Jan 1, 20080 citations

BEAM TRANSPORT AND STORAGE WITH COLD NEUTRAL ATOMS AND MOLECULES

P. L. Walstrom, Michael D. Di Rosa

A large class of cold neutral atoms and molecules is subject to magnetic field-gradient forces. In the presence of a field, hyperfine atomic states are split into several Zeeman levels. The slopes of these curves vs. field are the effective magnetic moments. By means of optical pumping in a field, Zeeman states of neutral lithium atoms and CaH molecules with effective magnetic moments of nearly {+-} one Bohr magneton can be selected. Particles in Zeeman states for which the energy increases with field are repelled by increasing fields; particles in states for which the energy decreases with field are attracted to increasing fields. For stable magnetic confinement, field-repelled states are required. Neutral-particle velocities in the present study are on the order of tens to hundreds of m/s and the magnetic fields needed for transport and injection are on the order of in the range of 0.01-1T. Many of the general concepts of charged-particle beam transport carry over into neutral particle spin-force optics, but with important differences. In general, the role of bending dipoles in charged particle optics is played by quadrupoles in neutral particle optics; the role of quadrupoles is played by sextupoles. The neutralparticle analog of charge-exchange injection into storage rings is the use of lasers to flip the state of particles from field-seeking to field-repelled. Preliminary tracking results for two neutral atom/molecule storage ring configurations are presented. It was found that orbit instabilities limit the confinment time in a racetrack-shaped ring with discrete magnetic elements with drift spaces between them; stable behavior was observed in a toroidal ring with a continuous sextupole field. An alternative concept using a linear sextupole or octupole channel with solenoids on the ends is presently being considered.A large class of cold neutral atoms and molecules is subject to magnetic field-gradient forces. In the presence of a field, hyperfine atomic states are split into several Zeeman levels. The slopes of these curves vs. field are the effective magnetic moments. By means of optical pumping in a field, Zeeman states of neutral lithium atoms and CaH molecules with effective magnetic moments of nearly {+-} one Bohr magneton can be selected. Particles in Zeeman states for which the energy increases with field are repelled by increasing fields; particles in states for which the energy decreases with field are attracted to increasing fields. For stable magnetic confinement, field-repelled states are required. Neutral-particle velocities in the present study are on the order of tens to hundreds of m/s and the magnetic fields needed for transport and injection are on the order of in the range of 0.01-1T. Many of the general concepts of charged-particle beam transport carry over into neutral particle spin-force optics, but with important differences. In general, the role of bending dipoles in charged particle optics is played by quadrupoles in neutral particle optics; the role of quadrupoles is played by sextupoles. The neutralparticle analog of charge-exchange injection into storage rings is the use of lasers to flip the state of particles from field-seeking to field-repelled. Preliminary tracking results for two neutral atom/molecule storage ring configurations are presented. It was found that orbit instabilities limit the confinment time in a racetrack-shaped ring with discrete magnetic elements with drift spaces between them; stable behavior was observed in a toroidal ring with a continuous sextupole field. An alternative concept using a linear sextupole or octupole channel with solenoids on the ends is presently being considered.

May 15, 20120 citations

{\mathrm{CS}}_{2}

molecules is redirected by sending it through the intensity gradient near the focus of a laser beam. We trace the direction of the molecules in the molecular beam, showing that the molecules that pass near the center of the high intensity laser beam will focus.