Rydberg-Stark deceleration of atoms and molecules

Abstract

The large electric dipole moments associated with highly excited Rydberg states of atoms and molecules make gas-phase samples in these states very well suited to deceleration and trapping using inhomogeneous electric fields. The methods of Rydberg-Stark deceleration with which this can be achieved are reviewed here. Using these techniques, the longitudinal motion of beams of atoms and molecules moving at speeds as high as 2500 m/s have been manipulated, with changes in kinetic energy of up to | E kin | = 1.3 × 10 −20 J (| E kin |/e = 80 meV or | E kin |/hc = 650 cm −1 ) achieved, while decelerated and trapped samples with number densities of 10 6 -10 7 cm −3 and translational temperatures of ∼ 150 mK have been prepared. Applications of these samples in areas of research at the interface between physics and physical chemistry are discussed.

Experimental progress in positronium laser physics

“…These large static electric dipole moments allow forces to be exerted on samples in these states using inhomogeneous electric fields [338]. In a spatially inhomogeneous electric field the resulting force is…”

“…It is generally the case that states with negative Stark shifts will ionize (at a given rate) in electric fields that are approximately half the strength of those required to ionize states with positive Stark shifts. The different ionization rates exhibited by states of differing n and k can be used to perform state-selective field ionization using static or pulsed electric fields [338]. …”

“…Thus, the manipulation of atoms and molecules in Rydberg states via inhomogeneous electric fields is now a well-developed research field [338]. An array of techniques have been developed to facilitate experimentation with many different atomic and molecular systems, but it is only recently that these ideas have been applied to Ps [136].…”

“…Longer term plans are being implemented which seek to replicate some of the experiments that have already been conducted in this area (e.g. [338,436,[454][455][456]459,[462][463][464]469]). …”

“…If this is done many times the atom may even be trapped. This technique has been demonstrated with polar molecules [447,448,596], and is even more effective with atoms or molecules excited to appropriate Rydberg states, as their dipole moments may be extremely large [338].…”