30, 20 and 10 Years Ago in OPN

“The microwave trap has the ability to trap any spin state ... In this first demonstration, laser-cooled cesium atoms, having a temperature below 5 μK, were trapped in the field of a resonant microwave cavity. The gradient of the microwave field intensity produced a spatial variation of the atom-microwave interaction energy that created a trap as deep as 100 μK. A small cloud of atoms released into such a trap oscillated about the trap center until collisions with hot, untrapped background gas atoms kicked the atoms out.”