A surface-electrode decelerator consisting of 44 electrodes has been used to decelerate supersonic beams of helium Rydberg atoms moving with an initial velocity of 1200 m/s. Prior to the deceleration, the helium atoms were excited from the
1s2s1S0 metastable state to selected Rydberg-Stark states with a narrow-band tunable UV laser. Complete deceleration could be achieved over a distance of 36 mm and in 60 $\ensuremath{\mu}$s, corresponding to an acceleration of $\ensuremath{-}2.0\ifmmode\times\else\texttimes\fi{}{10}^{7}$ m/s
2. After deceleration, the atoms were held in stationary electric traps above the chip surface, reaccelerated off the chip, and detected by pulsed electric-field ionization. The decelerator was also used to generate helium Rydberg-atom beams with a final velocity tunable between 0 and 1200 m/s. Transitions between low- and high-field-seeking Rydberg-Stark states were observed during trap loading and are attributed to adiabatic Landau-Zener dynamics at electric fields exceeding the Inglis-Teller field. By comparing the experimental results with the results of particle-trajectory simulations, the velocity distribution of the decelerated atoms was found to be characterized by temperatures ranging between 50 and 200 mK, depending on the magnitude of the electric dipole moment of the Rydberg-Stark states selected prior to the deceleration.
Beams of helium atoms in Rydberg states with principal quantum number
n=52, and traveling with an initial speed of 1950 m/s, have been accelerated, decelerated, and guided while confined in moving electric traps generated above a curved, surface-based electrical transmission line with a segmented center conductor. Experiments have been performed with atoms guided at constant speed, and with accelerations exceeding
107 m/s2. In each case, the manipulated atoms were detected by spatially resolved, pulsed electric field ionization. The effects of tangential and centripetal accelerations on the effective trapping potentials experienced by the atoms in the decelerator have been studied, with the resulting observations highlighting contributions from the density of excited Rydberg atoms to the acceleration, deceleration, and guiding efficiencies in the experiments.
The experimental realisation of a set of surface-based devices for controlling the positions and velocities of Rydberg atoms initially travelling in pulsed supersonic beams is described. The unique aspect of these devices is that they are based on the geometry of two-dimensional electrical transmission-lines and are therefore suited to integration with chip-based microwave circuits to realise a complete Rydberg laboratory on a chip. Such a chip-based laboratory could be exploited in hybrid approaches to quantum information processing, and for studies of collisions and decay processes of highly excited atoms and molecules. The devices operate through the generation of inhomogeneous electric fields and take advantage of the large electric dipole moments associated with high Rydberg states to exert forces on the atoms. In the experiments, helium atoms in Rydberg-Stark states with principal quantum numbers ranging from 48 to 52 and electric dipole moments of 10000 D are employed. The devices developed include electrostatic guides which permitted control over the transverse motion of beams of atoms. These were used to transport samples, initially travelling at 1950 m/s and deflect them away from their initial axis of propagation. The guided atoms were detected by pulsed electric field ionisation. To control the longitudinal motion of the samples, the transmission-lines were modified to permit the generation of sets of continuously moving electric traps. The resulting transmission-line decelerators were then employed to guide, accelerate and decelerate atoms trapped in three-dimensions. Accelerations up to 2.3 x 10^{7} m/s^{2} were applied to decelerate samples from 2000 m/s to zero-velocity in the laboratory-fixed frame of reference, leading to the removal of 80 meV of kinetic energy, the largest achieved in any Stark decelerator to date. The decelerated atoms were trapped in stationary electric traps and detected in situ. The phase-space acceptances of the decelerators were calculated to characterise the effects of acceleration and deceleration on the trapped atoms. The results of the calculations were employed in the interpretation of the experimental data, and to identify effects of collisions and blackbody transitions.