Measuring the force between 2 atoms

The handling of individual atoms is now possible in laboratory thanks to laser beams that are able to cool atoms to less than 0.001 K and optical clamps that allow the trapping of a single atom. The Van der Waals force between 2 atoms has been measured for the first time. 2 atoms have been trapped in 2 precise locations for a few seconds and their mutual interaction (the Van der Waals force) has been deduced from the perturbation of their Rabi oscillations. (A.C.)