Extremely cold atoms challenge entropy and refuse to heat

The dynamization on several occasions of a collection of ultra -color atoms should destroy their collective structure, but the quantum effects seem to counter the process.

The ultimate fate of any physical system should be a “thermalization”, a process by which everything warms up and becomes equal and without freshness, like an ice sculpture becoming a puddle. Intuitively, we assume that launching rocks on sculpture on several occasions could only accelerate this process, but Hanns-Christoph Nӓgerl at the University of Innsbruck in Germany and his colleagues launched an experience that has essentially done this to some of the coldest atoms of the planet and did not see them thermally.

“We expected to see the opposite,” says Nӓgerl. The researchers used approximately 100,000 cesium atoms which they have cooled in billions of degrees of absolute zero by hitting them with lasers and electromagnetic forces – at this temperature, the behavior of atoms is entirely quantum. The team organized the atoms in thousands of tubes at an atom. Then they started to “kick them” by shining an additional laser impetus on the atoms again and again.

Because these kicks gave the atoms of additional energy, they should have heated them and fly away with different speeds. The team member, Yanliang Guo, says they have never seen it happening, even if he and his colleagues have tried to apply different strength kicks and refined the strength of atoms interacted with each other. The atoms continued to move with a very similar speed, as if they were all “frozen” in a single quantum state.

The idea that quantum particles beat thermalization is not new – it dates from the 1950s – and the question of when it can happen has long fed the debates of physicists. The team member, Manuele Landini, said that the previous experiences that explored how kicks affect the atoms, if they warm up, finally revealed that they end up, but his team’s experience explored a different range of parameters, so he may have captured really new physics.

The mathematical theories of what is happening are also stimulating and conflicting. Adam Rançon at the University of Lille in France says that the calculation of the warming of interaction atoms is so difficult that researchers can often finish calculations for two or three atoms. There are ideas on how quantum states of atoms that interact very strongly can overlap in the right way to produce a state that does not absorb energy, but, in its opinion, the image is incomplete.

Experiences like the news can act like quantum simulators that can go further, but Rançon says that certain kick and interaction forces remain to be explored.

Robert Konik at the Brookhaven National Laboratory in New York worked on a mathematical model of a system like that of the new experience, which predicted the strange behavior of atoms. He says that the identification of systems that does not continue to absorb energy from kicks can also be inspired by new quantum technologies. Indeed, the quantum state in which atoms are stuck become durable and could be used reliably to detect or store information. “Thermalization is always the kiss of death with quantum effects,” he says.

Researchers are already working on follow -up experiences to organize atoms in thicker tubes and let them move between different tubes to see if it can “thaw” their speeds.