A team of researchers from the Massachusetts Institute of Technology (MIT) have cooled down sodium-potassium gas molecules to almost absolute zero. That makes them a million times colder than deep space. Brrr!
The study, published earlier this week, on Wednesday (June 10, 2015), informs that the exact temperature of the molecules is 500 nanokelvins (-459.7 degrees Fahrenheit), which is the closest to absolute zero that scientists have gotten to so far.
Absolute zero is a temperature impossible to achieve as it would require an unlimited amount of heat.
Martin Zwierlein, MIT physics professor and principal investigator at MIT’s Research Laboratory of Electronics, gave a statement in a press release informing that he and his team are really close to the temperature where quantum mechanics start to play a big role in the motion of molecules.
He went on to add that “these molecules would no longer run around like billiard balls, but move as quantum mechanical matter waves. And with ultracold molecules, you can get a huge variety of different states of matter, like superfluid crystals, which are crystalline, yet feel no friction, which is totally bizarre. This has not been observed so far, but predicted. We might not be far from seeing these effects, so we’re all excited”.
While the MIT team expected the temperature to cause the sodium-potassium molecules to exhibit exotic behavior, they were surprised to see that they were very much stable, long-lived and avoided collisions with other molecules.
Rather than rapidly rotating and vibrating as sodium-potassium molecules typically do, the low temperature caused the cold molecules to slow down to speeds that could be measure in centimeters per second.
The first thing that professor Zwierlein and his team did was to use lasers and evaporative cooling in order to cool down clouds of individual sodium atoms and individual potassium atoms to near absolute zero.
They then used a mechanism known as a Feshbach resonance that allowed them to bond the sodium and potassium atoms together with the help of a magnetic field, and formed ultracold sodium-potassium molecules. The principal investigator explained that the process is very similar to that of tuning a radio to be in resonance with a certain station.
Previous experiments that tried to cool down potassium rubidium molecules were unsuccessful due to the molecules chemically reactive, which cause the bonds between them to fall apart and led the molecules to collide with one and other.
The next step for the MIT team is to cool down the molecules by a factor of 10 in order to be able to start exploring their exotic properties.
Image Source: genesisnanotech.com