Take that, sports cars! Physicists at the National Institute of Standards and Technology (NIST) can accelerate their beryllium ions from zero to 100 miles per hour and stop them in just a few microseconds. What's more, the ions come to a complete stop and hardly feel the effects of the ride. And they're not just good for submicroscopic racing—NIST physicists think their zippy ions may be useful in future quantum computers.

The ions (electrically charged atoms) travel 100 times faster than was possible before across a few hundred micrometers in an ion trap—a single ion can go 370 micrometers in 8 microseconds, to be exact (about 100 miles per hour.)

Although ions can go much faster in accelerators, the NIST ions demonstrate precision control of fast acceleration and sudden stops in an ion trap. A close analogy is a marble resting at the bottom of a bowl, and the bowl suddenly accelerating (see animation). During the transport, the marble will oscillate back and forth relative to the center of the bowl. If the bowl is suddenly stopped at the right time, the marble will come to rest together with the bowl. Furthermore, the NIST researchers assured that their atomic marble's electron energy levels are not affected, which is important for a quantum computer, where information stored in these energy levels would need to be moved around without compromising the information content.


As described in Physical Review Letters,* NIST researchers cooled trapped ions to their lowest quantum energy state of motion and, in separate experiments, transported one and two ions across hundreds of micrometers in a multi-zone trap. Rapid acceleration excites the ions' oscillatory motion, which is undesirable, but researchers controlled the deceleration well enough to return the ions to their original quantum state when they came to a stop. A research group from Mainz, Germany, reports similar results.

