Nature Photon. http://doi.org/hww (2012)

Many precision experiments in physics and chemistry rely on the control of the particle velocities in atomic and molecular beams. Charged particles, atoms and molecules can be accelerated or decelerated using electric fields: Conor Maher-McWillams and colleagues show that atoms can also be accelerated using strong optical fields.

The idea behind the laser-driven linear accelerator designed by Maher-McWillams et al. is intuitive — atoms catch the optical waves created by the interference of two intense counter-propagating laser beams. As the waves pass through an atomic cloud, they accelerate batches of atoms that have the right initial positions and velocities, and by tuning the intensity and frequency of the lasers — tuning the waves — one can control the final velocity of the atoms. In their experiment, Maher-McWillams et al. accelerated argon atoms to velocities of hundreds of metres per second over micrometre distances in tens of nanoseconds.

Optical-wave surfing is not restricted to atoms. The technique could also be applied to a variety of molecular species, nanoscale particles and exotic atoms such as positronium and antihydrogen.