When it comes to shuttling individual atoms about, physicists have made giant strides in cooling, trapping and even collimating them into matter wave beams. These kinds of tricks are already being used for matter-wave interferometry on chips.
But if you want to do the same kinds of things with molecules, you’re out of luck. There are two problems. First, molecules are much harder to slow down and trap in decent quantities. And second, they are much more difficult to ID. Atoms are usually identified by the light emitted by electronic transitions, which are usually in the visible part of the spectrum. In most molecules, however, these transition are in the UV and so much harder to access.
Now Samuel Meek and friends from the Fritz-Haber Institute, a Max Plank Institute in Berlin, have tackled one of these problems by building a molecular decelerator on a chip. The device consists of an array of electrodes that create an electric field with a local minimum, or well, that polar molecules tend to fall into. The well can be moved along the array.
Decelerating molecules is then a matter of matching the velocity of the well to that of the incoming molecules and then rapidly slowing it down. Meek and co say that in this way they have halved the kinetic energy of carbon monoxide molecules by slowing them from 360m/s to 240m/s.
That’s impressive and the team reckons that with a little tweaking, the chip will be able to bring the CO molecules to a standstill.
Strangely, nobody has given much thought to what you can do with stationary CO molecules. One option is to use them to store qubits for quantum computing but there seem to be few other ideas.
Which means there’s a good opportunity here for a creative thinker to make a mark.
Ref: arxiv.org/abs/0812.1487: A Stark Decelerator on a Chip