Neutral atoms can be made to behave like charged particles by 'synthetic' electric and magnetic fields. These are created through the production of a synthetic gauge field in a state of matter known as a Bose–Einstein condensate (BEC), in which the atoms are all identical and behave collectively as if they were one 'superatom'.

Ian Spielman and his team at the National Institute of Standards and Technology in Gaithersburg, Maryland, have previously generated synthetic magnetic fields by spatial alteration of a time-independent electromagnetic vector potential — an entity that can be used to specify both the electric and the magnetic fields. Now they show that a synthetic electric field can be generated in a rubidium BEC in a parallel manner — by changing a spatially uniform vector potential over time.

The neutral atoms in the condensate were accelerated like charged particles in the synthetic electric field that was induced by changing the electromagnetic vector potential.

Nature Phys. doi:10.1038/nphys1954 (2011)