In a new study, scientists have created a novel state of matter in the unique microgravity environment of the International Space Station to explore the quantum world. In daily life, matter is usually presented in four states: gaseous, liquid, solid and plasma. However, there is also a fifth state of matter, bose-Einstein condensation (Bose-Einstein condensation, or BECs).
The velocity distribution data of the gaseous gamma atoms confirm the Bose-Einstein condensation discovered in 1995
Bose-Einstein condensation spans the everyday world controlled by classical physics and the microscopic world that 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 in two or more places at the same time. Because the Bose-Einstein condensate follows some quantum behavior, it is possible to provide scientists with key clues to the fundamentals of quantum mechanics, and possibly even to help establish the Theory of Everything, which explains how the universe works on the smallest to largest scale.
Now, in hundreds of laboratories around the world, scientists have been able to routinely create Bose-Einstein condensation. However, one of the limitations of this study is Earth’s gravity. These “superatoms” are so fragile and the devices that make them are so sophisticated that gravity on Earth can destroy them all, making it difficult to understand them.
As a result, researchers developed and successfully operated the Cold AtomicS Laboratory on the International Space Station, where they were able to produce bose-Einstein condensation in microgravity conditions. Launched in 2018, the lab is small and requires relatively little energy, thus meeting specific limits for the space station. On Earth, the equipment needed to make Bose-Einstein condensation can occupy the entire laboratory, but the cold atomic laboratory is only about the size. 4 cubic meters, requiring an average of 510 watts of electricity.
In the new study, researchers found through the Cold Atomics Laboratory that the bose-Einstein condensation of the bose-Einstein condensation time exceeded one second, greatly extending the observable time and improving the accuracy of the measurements. On Earth, by contrast, scientists have only a few tens of milliseconds to accomplish the same task. In addition, in microgravity, scientists can capture condensates with weaker forces, which in turn means that Bose-Einstein condensation can be produced at lower temperatures, at which point the peculiar quantum effect becomes more pronounced.
So far, researchers have used thorium atoms to create Bose-Einstein condensates. Robert Thompson, a physicist at the California Institute of Technology and a senior author of the study, said they eventually decided to add potassium atoms to study what happens when the two condensed states are mixed. In addition, the researchers are trying to create a spherical Bose-Einstein condensation state from the Cold Atomic Stakes, a form that can only occur in space.
“In the past, our main insights into nature’s internal operations have come from particle accelerators and observatories, and in the future, I believe that accurate measurements of cold atoms will play an increasingly important role,” Thompson added. Their detailed findings were published June 11 in the journal Nature.
What is Bose-Einstein condensation?
The Bose-Einstein condensation state (BEC) is called the fifth state of matter, while the first four are solid, liquid, gaseous, and plasma. This state is formed at low temperatures close to absolute zero and only in atoms that behave like bosons.
A boson is one of two elementary particles. When boson atoms cool down to form a condensed state, they lose their properties, acting like a giant superatomic cluster, a bit like a photon that becomes indistinguishable in a laser beam. On June 5, 1995, Eric Cornell and Carl Wyman of the University of Colorado at Boulder experimented to create the first Bose-Einstein condensation. Four months later, Wolfgang Kotler of the Massachusetts Institute of Technology independently obtained Bose-Einstein condensation using sodium-23. In 2001, Cornell, Wyman and Ketler shared the Nobel Prize in Physics.
Although Bose-Einstein condensation is difficult to understand and difficult to make, they have many very interesting features. For example, they can achieve abnormally high optical density differences. In general, the refractive coefficient of a condensed body is very small because its density is much smaller than the usual solid. But the use of lasers can change the atomic state of Bose-Einstein condensation, causing it to suddenly increase the refractive coefficient of a certain frequency. As a result, the speed of light in the condensation will plummet, even to several meters per second.
The spin-off-Einstein condensation can be used as a model of a black hole, and the incident light does not escape. Bose-Einstein condensation can also be used to “freeze” light, which is released when condensed and decomposed.