Due to its cryogenic technology, liquid helium has been used as a coolant for nearly a century in research and applications that require extremely low temperatures, from medical devices to deep space exploration.
However, helium is a scarce resource and is in increasing demand for use in high-tech industries. This is especially true for helium-3. Helium-3 is a rare isotope that is more effective as a coolant in extreme conditions and is primarily obtained from aging nuclear warheads.
What is quantum computing and how does it work?
What is quantum computing and how does it work?
Driven by the need to find an alternative to helium-based cooling systems, an international team led by researchers from the Institute of Chinese Academy of Sciences in Beijing began searching for solid-state materials that can achieve large energy changes by changing state. .
After years of experimentation, they discovered a “supersolid,” a cobalt-based quantum magnetic material that has a solid structure but behaves like a fluid.
But scientists said it has also been observed cooling below 1 Kelvin and could be used to achieve ultra-low temperatures.
According to the third law of thermodynamics, the lowest possible temperature in physics is -273 degrees Celsius, or 0 Kelvin (-459 degrees Fahrenheit). Physicists define ultracold temperatures as between 0 Kelvin and 4.2 Kelvin, the range needed to develop cutting-edge technologies, including quantum computing.
“This is truly a new frontier,” said Sun Peijie, a professor at CAS’s Beijing National Institute of Condensed Matter Physics and co-corresponding author of the study.
He said it was only in recent years that scientists realized the possibility of using solids to achieve ultra-low temperatures, and that this research was only being carried out by a small number of scientists around the world. .
China’s cutting-edge quantum computer becomes ‘top list of US users’ after becoming popular worldwide
China’s cutting-edge quantum computer becomes ‘top list of US users’ after becoming popular worldwide
The research team’s findings were published in the peer-reviewed journal Nature on January 11th. The research was carried out by scientists from research institutions including the CAS laboratory, Peking University’s Department of Physics, and France’s Laue-Langevin Institute Jülich Center for Neutron Science.
“This study shows that it is theoretically possible to achieve cryogenic temperatures without relying on helium,” Sun said.
A shortage of helium, especially helium-3, is a challenge for China as it races to develop quantum technology.
In 2022, 94 percent of China’s helium will be imported, mostly from Qatar, followed by the United States and Australia.
Sun said China “doesn’t have any helium-3 and almost always relies on Russia and the United States for the isotope.”
But he said the team’s progress should not be overstated and that helium cannot be replaced yet. He said it is still in its early stages and the material has limitations, including having to use it in environments where temperatures are already around 4 degrees Kelvin.
Most quantum machines, from computers to satellites, use fundamental units of information called quantum bits or qubits, similar to the digital bits used in classical computing. But qubits are sensitive and easily perturbed by heat, so they must be kept at extremely low temperatures, close to 0 Kelvin.
“All quantum technologies, including quantum communications and quantum computing, almost universally require ultra-cold environments,” Sun said.
Creating that environment requires a dilution refrigerator, which has become increasingly difficult for China to obtain from overseas in recent years, Sun said. That “significantly hinders the development of China’s quantum technology,” he said.
China-led experiment raises doubts about US’s ‘room temperature’ superconductor
China-led experiment raises doubts about US’s ‘room temperature’ superconductor
The Chinese government has made supporting Chinese production of this key technology a national priority, and significant investment has already been made. Origin Quantum became the latest Chinese company to announce production of dilution refrigerators in October, according to a report in the state-run Science and Technology Daily.
Sun said the team has reproduced the experiment and developed a device for application in specific environments, but there is still a long way to go before it can be widely applied, and engineering challenges must be overcome. pointed out that it was necessary.
He said this study could be a starting point for further discussion and research in fundamental physics.
“For half a century it has been thought that supersolids exist, and now somehow we have confirmed it,” Sun said. “It could lead scientists to look for new evidence from other materials, which could ultimately advance physics.”