MIT Creates Super-Chilled Molecules, Colder Than Interstellar Space

Justin Streight

MIT scientists used lasers to create the coldest substance known to man, super-chilled sodium potassium gas molecules, hitting temperatures of minus 459.67 degrees Fahrenheit (273.15 degrees Celsius). It might sound like a strange thing to do, but the researchers explain that very cold things can be very useful to humanity -- and bizarre.

According to Yahoo News, the MIT researchers first cooled and combined sodium and potassium into molecules using magnetic fields -- the atoms usually repulse each other since they're both positively charged. Only those chemically unstable molecules have been chilled to super cold temperatures so far.

Then, using two lasers, one high-energy beam set the molecule's initial vibrating state and another low energy beam, they sucked the heat away from the substance. The scientists reportedly reached 500 nanokelvins, 500-billionths of a degree above absolute zero.

That's a million times colder than interstellar space. The scientists held that temperature for 2.5 seconds, a lifetime for unnaturally frozen molecules.

So, why make super-chilled molecules?

At extremely low temperatures, matter ceases to act like ordinary matter and takes on unusual states beyond just being a solid, liquid, or gas. For example, extreme cold helium becomes a liquid with no viscosity -- a superfluid.

MIT physics professor Martin Zwierlein explained that he had hoped to see superfluid crystals with sodium-potassium molecules. It hasn't been observed yet, but he feels they're close.

"So 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."
"The molecules could be used as quantum bits, where '0' and '1' is robustly encoded in the rotation of the molecules. Quantum computation itself would be extremely important for cryptography and to solve certain types of problems that simply take impossibly long on a 'classical' computer."

MIT's research on super-chilled molecules is described more in detail in a paper published in the journal Physical Review Letters on May 18.

[Image Credit: NASA / ESA]