In Search of Really Small Tweezers.(working with atoms)

How do you put an atom to work? Unlike, say, a bowling ball, which has three holes for your fingers, atoms are hard to get a handle on. When scientists from Caltech set out to fashion a laser from a single atom, a big challenge was how to keep the atom still. In a recent paper in Nature, they describe rigging up an elaborate contraption of laser beams and mirrors merely to hold a cesium atom in place long enough-- about 100 thousandths of a second--to perform their experiment.

This masterful balancing act shows how difficult atoms can be. But dealing with them is becoming a top priority in research labs. The reason is simple: as machines get smaller, the parts are smaller still, and they're getting hard to handle. Computer chips (a kind of electrical machine) already contain wires that are only a few atoms wide. And if scientists ever figure out how to make a quantum computer, which would use atoms or molecules as computing elements, they're going to need a way to assemble it.

A promising technique for getting atoms to do what you want is self- assembly. It involves taking advantage of the natural tendency of atoms and molecules to arrange themselves in certain ways. Life, in a sense, is an act of self-assembly: DNA, a complex molecule, naturally organizes itself in certain ways because its various components react according to laws of chemistry.

Scientists, of ...