The figure shows the saddle-type field structure of the Paul trap which may keep a single particle captured.

Since these techniques are available, the high precision of measurements in the atomic range contributed in the rise of completely new research fields. By means of the Paul trap, for example, it should be possible to realize a single-atom clock with thousendfold precision as compared with present-day atomic clocks. The ring trap, a 'scion' of the Paul trap, is used today mainly for fundamental studies into the quantum computer, in a modified form also for investigations of the non-classical light of a single-ion laser. Using the Ioffe-Pritchard trap, Bose-Einstein condensates may be produced.