We present a novel approach to the preparation of neutral (anti-)matter. The scheme is based on recombination of a free electron and an ion, and can be considered as the inverse of pulsed field ionization. We have obtained promising results on rubidium: at low densities already efficiencies of 0.3% were obtained. This is orders of magnitude more than has been achieved in previous recombination studies.

Phys. Rev. Lett.

Wesdorp, C., Robicheaux, F., & Noordam, L. D. (2000). Field-induced electron-ion recombination: A novel route towards neutral (anti-)matter. Phys.Rev.Lett., 84, 3799–3802.