Chinese helium cooling system: Shanghai researchers claim to have invented a chiller that uses an abundant isotope to produce super-cold temperatures.
However, additional study is required before it can be employed in widespread applications.
Shanghai researchers claim to have built a gadget that can produce extremely low temperatures, allowing cutting-edge technology such as quantum computers to become more readily available.
Most quantum machines, from computers to satellites, have fundamental components that detect and manipulate subatomic particles that are easily affected by heat and must operate at temperatures close to absolute zero.
Helium-3, an isotope of helium that can carry heat away with unrivalled efficiency, is required to cool the most modern quantum electronics.
However, helium-3 is extremely uncommon on Earth, and the only source is old nuclear weapons.
Helium-3 is in high demand for quantum research and other revolutionary technologies. Its price has climbed more than 40-fold in less than two decades, to nearly US$5,000 per litre in gas form.
Even yet, it is not available to the general public. Helium-3, for example, is one of the few commodities subject to rigorous government production and distribution limitations on military grounds in the United States.
Professor Dang Haizheng and colleagues from the Shanghai Institute of Technical Physics at the Chinese Academy of Sciences said they had built a powerful chiller for some of the most demanding quantum machines without using any helium-3 at all in a paper published in the Chinese peer-reviewed Science Bulletin on Wednesday.
Another helium isotope, helium-4, is used as the coolant in the novel cooling system.
The gas used in party balloons, helium-4, is far more abundant than helium-3, but it is less effective as a cooling agent in severe temperatures.
Helium-4 becomes a superfluid when temperatures drop below 2 kelvin (-271 degrees Celsius), climbing walls against gravity and becoming much more difficult to manage.
Dang’s group created a theoretical model that may predict the behaviour of helium-4 flow in a superfluid state to some extent.
The chiller they constructed is similar in essence to a residential refrigerator, but it has fewer moving parts. To improve heat-transfer efficiency, it is powered by a pulse energy source and works at a high frequency.
The chiller features a specific component to inhibit the antigravity rise, which helps to control the helium-4’s unpredictable behaviour.
According to the experts, a portion of the device must be made of extremely high-quality components with precision double that of today’s mainstream devices.
The new cooling system preserved a superconducting nanowire single-photon detector, an optical sensor typically employed in quantum machines, at 1.8 kelvin for more than two weeks in their experiment (15 days).
According to the researchers, the findings indicated that helium-4 has the potential to totally replace helium-3 in some of the most demanding applications, such as a space trip.
“This is fantastic news,” stated an anonymous quantum physicist in Hefei, Anhui province.
According to the researcher’s approximate estimate, finding a helium-3 alternative might cut the cost of quantum technology in radars by at least 10%.
The use of helium-4 would help remove a key barrier to the widespread implementation of quantum technology, but the novel cooling device’s dependability remains a concern because the experiment was carried out in a lab.
“A good product must perform flawlessly in tough situations for years,” he stated.
In recent years, China has made a substantial contribution to the development of quantum technologies.
Chinese researchers have created the world’s first quantum satellite, the world’s longest quantum communication network, the world’s farthest-ranging quantum radar, and the world’s fastest quantum computers with government financing.
All of these advancements relied on helium-3-cooled sensors.
However, the practical use of these technologies is still limited.
With a mix of government and private support, some Chinese researchers, including Dang’s team, have created their own start-ups to speed up the commercialisation of the technology.