In a significant success, physicists have produced a two-dimensional supersolid in the laboratory for the first time.
It may sound amazing, but it is a feat that researchers have been working on for over 50 years. Supersolids are foreign materials with atoms arranged in the ordered structure of a solid, but they can flow without friction, like a superfluid.
Two years ago, physicists successfully created supersolids with ultra-cold magnetic atoms … but only in one dimension. Now, a team of Austrian researchers has for the first time managed to create a 2D crystal-like structure; the result will allow physicists to experiment and experiment with some of the strangest materials science phenomena out there.
“To imagine a supersolid, consider an ice cube submerged in liquid water, with a frictionless water flow through the cube,” writes physicist Bruno Laburthe-Tolra of the Paris Laser Physics Laboratory in a News article & Views posted next to the new paper inside Nature today.
This strange duality means that supersolids are known as a quantum mechanical state of matter.
This is because, as with other quantum phenomena (think entanglement or the Schrödinger cat), particles in the supersolid state are trapped in a rigid solid structure, but also delocalized at the same time, allowing them to behave. be like a wave and flow freely. without friction along the solid.
Supersolidity was first predicted in 1969 and has long been studied on superfluid helium, which was considered the best candidate to find evidence of a solid, crystal-like structure with properties of a superfluid. However, despite decades of research, the supersolidity of helium remains elusive.
More recently, researchers have focused their attention on ultra-cold quantum gases: clouds of strongly magnetic atoms that cool to absolute zero. The fact that these atoms are magnetized means that they interact in unique ways that can lead to this strange quantum mechanical state of supersolidate.
“Normally, one would think that each atom would be in a specific droplet, with no way to move,” says the physicist involved in the new Matthew Norcia breakthrough at the University of Innsbruck in Austria.
“However, in the supersolid state, each particle dislocates in all the droplets, existing simultaneously in each droplet. So you basically have a system with a series of high-density regions (the droplets) that share all the same delocalized atoms. ”
Although the Austrian team, led by quantum physics Francesca Ferlaino, of the University of Innsbruck and the Austrian Academy of Sciences, was one of several that created a chain of drops along a dimension that demonstrated their super solidity in 2019, they needed to modify their magnetic model in order to create a 2D version, with two or more rows of drops.
This latest achievement opens up the phenomena they can study with these strange clouds of gas.
“For example, in a two-dimensional supersolid system, you can study how vortices form in the hole between several adjacent drops,” Norcia says.
“These vortices described in theory have not yet been demonstrated, but they represent an important consequence of superfluity.”
There is still much to learn about this strange supersolid quantum gas; for example, researchers are unsure whether they could make a larger supersolid, as the state of matter is incredibly sensitive to the magnetic trap they have created.
But for now, the fact that the team has managed to create the first supersolid in 2D is a huge feat in itself, which will inevitably lead to a greater understanding of this strange state of matter and the invisible quantum forces that govern it. our reality.
The research has been published in Nature.