A team led by T. Pfau and T. Langen at the Institute of Physics (University of Stuttgart) succeeded in demonstrating for the first time that the long-predicted supersolid state of matter actually exists. The researchers describe their findings in the journal Nature.
What is a supersolid?
In everyday life, we deal with four states of matter: solid, liquid, gas, and plasma. Many intermediate states are known to exist, such as liquid crystal, and some states only exist theoretically or under extreme conditions. A supersolid is a paradoxical state of matter that combines the solid and liquid in the same body. In other words, a supersolid is a fluid-like crystal, which combines the frictionless flow of a superfluid with the crystal-like periodic density modulation of a solid. Supersolid is immune to many of the forces that constrain ordinary liquids. Some liquids close to absolute zero flow without friction and this state is described as superfluid. This was discovered in 1937 for helium. A supersolid is a spatially ordered material (that is, a solid or crystal) with superfluid properties. A supersolid is able to move without friction but retains a rigid shape. Quantum mechanic is involved in explaining these two particular states of matter.
What is news about the supersolid?
As we have pointed out above, the team from the Institute of Physics of the University of Stuttgart has demonstrated that supersolid is not only theory but such state of matter actually exists. The researchers have experimentally proved that. In the photo below we can see the experimental setup, which is made by the Stuttgart researchers, and with which they succeeded in using lasers and magnetic fields to produce the supersolid from dysprosium atoms (dysprosium is a chemical element – Dy). Finally, to prove that the obtained supersolid from the experiment is really a supersolid, researchers study the two types of sound waves traveling through the supersolid with different velocities of sound waves.
