Approaching absolute zero without helium15th January 2024
CHINA: Chinese scientists claim to have synthesised a supersolid material that can be cooled to near absolute zero without relying on increasingly scarce helium.
Said to be the first evidence of supersolidity in a real-world solid material, if confirmed this groundbreaking discovery has the potential to revolutionise cooling technology.
A supersolid is a special spatially-ordered quantum state of matter where particlest also flow with zero viscosity.
This newly synthesised supersolid, Na2BaCo(PO4)2, is said to possess a giant magnetocaloric effect being capable of cooling to near absolute zero (-273.15ºC), the coldest possible temperature, without needing helium.
Helium is currently required for advanced research and technologies like superconducting magnets and MRI machines. However, with limited reserves and rising extraction costs, scientists and industries face a helium shortage.
Describing their research, Prof Su Gang of the University of Chinese Academy of Sciences, one of the lead scientists of the scientific team, said: “We put this material into magnetic fields and then tried to remove the fields while keeping the heat from leaking. As we slowly reduce the magnetic fields, the temperature of the material also lowered slowly, eventually reaching 94mK.”
The concept of supersolidity has been occupying physicists since the 1970s, but proving its existence in real materials has remained elusive.
This new study is published in the scientific journal Nature.