Cold neutral atoms via charge exchange from excited state positronium: a proposal

Abstract

We present a method for generating cold neutral atoms via charge exchange reactions between trapped ions and Rydberg positronium. The high charge exchange reaction cross section leads to efficient neutralisation of the ions and since the positronium-ion mass ratio is small, the neutrals do not gain appreciable kinetic energy in the process. When the original ions are cold the reaction produces neutrals that can be trapped or further manipulated with electromagnetic fields. Because a wide range of species can be targeted we envisage that our scheme may enable experiments at low temperature that have been hitherto intractable due to a lack of cooling methods. We present an estimate for achievable temperatures, neutral number and density in an experiment where the neutrals are formed at a milli-Kelvin temperature from either directly or sympathetically cooled ions confined on an ion chip. The neutrals may then be confined by their magnetic moment in a co-located magnetic minimum well also formed on the chip. We discuss general experimental requirements.

References in corpus (5)

• Bose-Einstein condensation of chromium
• Sub-millikelvin dipolar molecules in a radio-frequency magneto-optical trap
• Optoelectrical cooling of polar molecules to sub-millikelvin temperatures
• Cross Section for Rydberg Antihydrogen Production via Charge Exchange Between Rydberg Positronium and Antiprotons in Magnetic Field
• Cold molecular ions on a chip