Radiative forces from near-resonant laser light can be used for cooling and slowing the motion of diatomic molecules. While radiative-force slowing can be efficient in reducing the longitudinal velocity of molecules in a beam, this method has so far resulted in relatively low fluxes of slow molecules available for loading into a trap. This is primarily due to the divergence of the molecular beam, which increases in inverse proportion to the forward velocity. In this paper, we discuss methods to transversely confine molecules as they are slowed by radiative forces. We focus in particular on a promising method that uses a microwave field tuned to the blue of a rotational transition in the molecule, to provide the confining force.We argue that with a realistic design, this approach can improve the useful flux of slow molecules from radiative slowing by a factor of ∼100.Radiative forces from near-resonant laser light can be used for cooling and slowing the motion of diatomic molecules. While radiative-force slowing can be efficient in reducing the longitudinal velocity of molecules in a beam, this method has so far resulted in relatively low fluxes of slow molecules available for loading into a trap. This is primarily due to the divergence of the molecular beam, which increases in inverse proportion to the forward velocity. In this paper, we discuss methods to transversely confine molecules as they are slowed by radiative forces. We focus in particular on a promising method that uses a microwave field tuned to the blue of a rotational transition in the molecule, to provide the confining force.We argue that with a realistic design, this approach can improve the useful flux of slow molecules from radiative slowing by a factor of ∼100.

Molecular PhysicsJun 14, 201316 citations

Kinematic Slowing of Molecules Formed by Reactive Collisions

Ningning Liu, H. J. Loesch

We report the generation of a beam of slow (translationally cold) KBr molecules formed by exoergic reactive collisions in counterpropagating beams of K atoms and HBr molecules. The intensity of the slow beam is estimated to $4\ifmmode\times\else\texttimes\fi{}{10}^{11}\text{ }\text{ }{\mathrm{s}}^{\ensuremath{-}1}\text{ }{\mathrm{sr}}^{\ensuremath{-}1}$. The velocity distribution (density) peaks at $42.5\text{ }\text{ }\mathrm{m}/\mathrm{s}$ corresponding to a formal temperature of 13 K. About 7% of the molecules move at velocities between 14.2 and $20\text{ }\text{ }\mathrm{m}/\mathrm{s}$ and an estimated fraction of 7% is slower than $14.2\text{ }\text{ }\mathrm{m}/\mathrm{s}$ .We report the generation of a beam of slow (translationally cold) KBr molecules formed by exoergic reactive collisions in counterpropagating beams of K atoms and HBr molecules. The intensity of the slow beam is estimated to $4\ifmmode\times\else\texttimes\fi{}{10}^{11}\text{ }\text{ }{\mathrm{s}}^{\ensuremath{-}1}\text{ }{\mathrm{sr}}^{\ensuremath{-}1}$. The velocity distribution (density) peaks at $42.5\text{ }\text{ }\mathrm{m}/\mathrm{s}$ corresponding to a formal temperature of 13 K. About 7% of the molecules move at velocities between 14.2 and $20\text{ }\text{ }\mathrm{m}/\mathrm{s}$ and an estimated fraction of 7% is slower than $14.2\text{ }\text{ }\mathrm{m}/\mathrm{s}$.

Physical Review LettersMar 8, 200726 citations

Taming molecular beams

Sebastiaan Y. T. van de Meerakker, Hendrick L. Bethlem, Gerard Meijer

Nature PhysicsAug 1, 2008244 citations

42.5\text{ }\text{ }\mathrm{m}/\mathrm{s}

corresponding to a formal temperature of 13 K. About 7% of the molecules move at velocities between 14.2 and

20\text{ }\text{ }\mathrm{m}/\mathrm{s}

and an estimated fraction of 7% is slower than

14.2\text{ }\text{ }\mathrm{m}/\mathrm{s}