There are four common states of matter in everyday life – gases, liquids, solids and plasmas. However, there is also a fifth state of matter – Bose-Einstein condensates (BEC), which scientists created for the first time in the laboratory 25 years ago. When a group of atoms is cooled to near absolute zero, the atoms begin to clump together, behaving as if they were a large “super-atom”.
Bose-Einstein condensates straddle the border between the everyday world, governed by classical physics, and the microscopic world, which follows the rules of quantum mechanics. In the world of quantum mechanics, a particle can behave as if it were spinning in two opposite directions at the same time, or as if it existed in two or more locations simultaneously. Because they follow some of these quantum behaviors, Bose-Einstein condensates can offer scientists key clues to how quantum mechanics work, potentially helping to solve mysteries such as how to create a “theory of everything” which could explain the functioning of the cosmos from the smallest to the largest scale.
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Scientists are now regularly creating Bose-Einstein condensates in hundreds of laboratories around the world. However, one limitation that hinders this research is gravity. These “super atoms” are extraordinarily fragile and the configurations used to create them are incredibly delicate, so the pull of gravity felt on Earth can disrupt both, making it difficult to learn much about them.
As such, the researchers developed the Cold Atom Lab, which can generate Bose-Einstein condensates in microgravity found in orbit aboard the space station. Launched in 2018, the Cold Atom Lab is small and requires only a relatively small amount of energy, so it meets the specific constraints on board the space station. While the equipment originally needed to create Bose-Einstein condensate on Earth can occupy an entire laboratory, the Cold Atom Lab takes only about 14 cubic feet (0.4 cubic meters) and requires a total of an average of 510 watts of power.
Using the Cold Atom Lab, researchers in a new study have discovered that they can increase the time that they can analyze these condensates after the traps containing the material are extinguished to more than a second. By comparison, on Earth, scientists would only have a hundredths of a second for the same task.
In addition, in microgravity, scientists have found that they need weaker forces to trap condensate. This, in turn, means that they could create condensate at lower temperatures. And, at these temperatures, the exotic quantum effects would become more and more pronounced.
So far with this study, researchers have created Bose-Einstein condensates using rubidium atoms. Ultimately, they also aim to add potassium atoms to investigate what happens when two condensates mix, the study’s lead author Robert Thompson, a physicist at the California Institute of Technology in Pasadena, told Space.com . In addition, scientists are now looking to use the Cold Atom Lab to create spherical Bose-Einstein condensates, which can only be created in space, added Thompson.
“In the past, our main insights into the inner workings of nature have come from particle accelerators and astronomical observatories; In the future, I believe that precision measurements using cold atoms will play an increasingly important role, “said Thompson.
Scientists have detailed their discoveries in the June 11 issue of the journal Nature.