A team of researchers at the Northwestern University have developed a new laser cooling technique which has helped them successfully stop a trapped molecule, in a rotating mode, in its tracks.
Scientists see the development as a major breakthrough. They explain trapping of molecules is relatively easy with the help of laser beams but the problem is despite being trapped they continue rotating, giving false impression that they are free. But the cooling technique has helped in trapping molecules while keeping control on their rotation.
Lead researcher Brian Odom said, “It is counterintuitive that the molecule gets colder and not hotter when we shine intense laser light over it. The spectrum of a broadband laser is modified so that nearly all the rotational energy is removed from the illuminated molecules.”
“We are the first to stop molecular tumbling in such a powerful yet simple way,” added Odom, an assistant professor of physics and astronomy at the Weinberg College of Arts and Sciences.
According to Odom, trapping of many types of molecules is not a tedious task but the process which is difficult is holding them precisely in place and stop their rotation.
For the experiment, the research team cooled singly charged aluminum monohydride molecules using their customized laser from room temperature to – 452 F. The complete process of cooling took just fraction of a second.
Scientists explain the sudden drop in the temperatures stopped the molecules’ normally persistent tumbling motion in its tracks.
Scientists say control of molecules and their vibrational and rotational states is important during the construction of superfast quantum computers.
The processing power of these computers would be exponentially faster than today’s computers.
Odom said that they chose singly charged aluminum monohydride molecules for the experiment as they do not vibrate when they come in contact with a laser.
He further said the selection of right molecule helped the team to get good results as they successfully stopped the molecules from rotating without giving unnecessary attention to the vibrations.
The details of the experiment have been published today in Nature Communications.