Chinese scientists have achieved ultra-low temperature refrigeration without the use of liquid helium, which is expected to have great application prospects in high-tech fields such as deep space exploration, quantum technologies and materials science.
Ultra-low temperature refrigeration using liquid helium was invented over a century ago.
However, due to the relative scarcity of helium in nature, it has become an important challenge within the scientific community to achieve ultra-low temperature refrigeration without using helium.
Researchers used a triangular-lattice cobaltate material to realize the helium-free cooling to a temperature of 94 millikelvin (minus 273.056 C).
Supersolid is a quantum state exhibited by matter at very low temperatures approaching absolute zero (minus 273.15 C).
Chinese researchers from several scientific research institutes worked on the project including the University of Chinese Academy of Sciences, the Institute of Physics and the Institute of Theoretical Physics, Chinese Academy of Sciences.
The research result has been published in the scientific journal Nature.