On the electrostatic deceleration of argon atoms in high Rydberg states by time-dependent inhomogeneous electric fields

Abstract

Argon atoms in a pulsed supersonic expansion are prepared in selected Stark components of Rydberg states with effective principal quantum number in the range n* = 15–25. When traversing regions of inhomogeneous electric fields, these atoms get accelerated or decelerated depending on whether the Stark states are low- or high-field seeking states. Using a compact electrode design, which enables the application of highly inhomogeneous and time-dependent electric fields, the Rydberg atoms experience kinetic energy changes of up to 1.2 × 10−21 J (i.e. 60 cm−1 in spectroscopic units) in a single acceleration/deceleration stage of 3 mm length. The resulting differences in the velocities of the low- and high-field seeking states are large enough that the corresponding distributions of times of flight to the Rydberg particle detector are fully separated. As a result, efficient spectral searches of the Rydberg states best suited for acceleration/deceleration experiments are possible. Numerical simulations of the particle trajectories are used to analyse the time-of-flight distributions and to optimize the time dependence of the inhomogeneous electric fields. The decay of the Rydberg states by fluorescence, collisions and transitions induced by black-body radiation takes place on a timescale long enough not to interfere significantly with the deceleration during the first ∼5 µs.

Experimental progress in positronium laser physics

“…A few years later, longitudinal acceleration and deceleration of H 2 beams using static electric fields was also achieved, by the same group [455]. The use of time-dependent electric fields to control Rydberg atoms and molecules was introduced by Vliegen et al [456] in 2005. This work allowed control over the translational motion of hydrogenic [457] and non-hydrogenic [458] atoms, as well as the realization of a wide range of atom optics elements, including mirrors [459], lenses [457], deflectors [460,461], decelerators and traps [436,[462][463][464][465][466].…”

“…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]). …”

Magnetic Trapping of Hydrogen after Multistage Zeeman Deceleration

“…This work led to electrostatic trapping of Stark-decelerated samples of ammonia at temperatures of $30 mK [4] and to the determination of the lifetime of the metastable a 3 Å state of CO [5]. Polar OH molecules have also been loaded into electrostatic [6] and magnetoelectrostatic [7] traps following multistage Stark deceleration.Rydberg Stark deceleration has also been used to decelerate [8,9] and electrostatically trap samples excited to well-defined Rydberg states at temperatures of $150 mK [10], while maintaining the phase-space density of the initially excited bunch. The development of the technique of multistage Zeeman deceleration [11][12][13][14][15][16], the magnetic analogue of multistage Stark deceleration has expanded the range of species which can be adiabatically decelerated to include all paramagnetic atoms and molecules.…”

“…Rydberg Stark deceleration has also been used to decelerate [8,9] and electrostatically trap samples excited to well-defined Rydberg states at temperatures of $150 mK [10], while maintaining the phase-space density of the initially excited bunch. The development of the technique of multistage Zeeman deceleration [11][12][13][14][15][16], the magnetic analogue of multistage Stark deceleration has expanded the range of species which can be adiabatically decelerated to include all paramagnetic atoms and molecules.…”

Molecules on a string

“…Such methods have enabled the deflection of Kr beams [22], the partial deceleration of H 2 [23,24] and Ar [25,26] beams, and the reflection [27] and trapping [16,28] of H atoms. The ability to control the translational motion of Rydberg atoms and molecules is of interest to a wide range of disciplines, with potential applications in experiments on antihydrogen [29], ultracold plasmas [30], and quantum information processing [31].…”