The entry of superconducting quantum computers into the quantum era means that we can solve many problems that cannot be solved by ordinary computers, such as artificial intelligence, new materials, new drugs, new energy, and so on. But to make superconducting quantum computers work stably, a state-of-the-art ultra-low temperature refrigeration technology is needed, and this ultra-low temperature refrigeration technology is daunting, that is, "dilution refrigeration technology".
However, just when people thought that this technology could not be broken through, Chinese scientists proved with practical actions that the situation of technological blockade can be broken. They overcame one insurmountable difficulty after another from scratch, and finally, in people's expectations, a world-leading high-tech equipment, China's domestic dilution refrigerator successfully rolled off the assembly line, which can provide an extremely low temperature environment for our superconducting quantum computer, creating infinite possibilities, let us take a look at where the technology is here. It's also a triumph for technology.
First, the core technical background.
A quantum computer is a supercomputer that runs extremely fast and can process large amounts of data, and it far surpasses traditional computers in its ability to solve a variety of complex problems, such as solving problems related to communication encryption, drug design, artificial intelligence, etc. People have always been full of yearning for this kind of magical computer, and the superconducting quantum computer is a kind of quantum computer, which not only has ultra-fast running speed by virtue of the material of superconducting technology, but also can perform massive calculations without affecting the work.
However, although the "dream" index of superconducting quantum computers has always attracted the attention of mankind, the ensuing problem of ultra-low temperature refrigeration has also caused headaches for mankind. Superconducting materials can only achieve zero resistance at low temperatures, which means that they can only perform at the critical point of absolute zero, but to keep it at this extremely low temperature, an efficient and stable refrigeration equipment is required.
The heavy problem has been placed in front of people, just like playing a game, the newly upgraded quantum technology, and encountered the neck of the extremely low temperature refrigeration level, and the most difficult level is undoubtedly the dilution refrigeration level, it is a state-of-the-art ultra-low temperature refrigeration technology, only through this technology, we can make the superconducting quantum computer successfully and stably, but how difficult it is to overcome this level.
2. Dilution refrigeration technology.
Dilution refrigeration technology refers to the use of helium 3 and helium 4 in a mixed state at extremely low temperatures, through the law of fluid thermodynamics to create an ultra-low temperature environment, and in order to achieve this extremely low temperature, a super refrigeration equipment is needed, and this equipment is what we call the "dilution refrigerator".
The dilution refrigerator can not only produce a "near-critical" temperature, but also reduce the impact of impurities at ultra-low temperatures, ensure the best environment for superconducting materials, and in this extremely low temperature environment in the quantum state, humans can observe some wonderful quantum phenomena, which not only helps us understand the quantum world, but also helps us discover some unprecedented scientific phenomena and enrich our scientific knowledge.
Dilution refrigeration technology looks simple, but if it wants to play the best effect in practical application, it needs a complex and efficient equipment to achieve, including various components of the dilution refrigerator, such as vacuum pumps, heat exchangers, shielded magnetic fields, etc., all need to have advanced technology, and human beings want to achieve such high-end equipment, but also need to comprehensively use the knowledge of mechanical, physical, chemical and other disciplines, and combine advanced manufacturing technology to develop a dilution refrigerator that meets the requirements.
The main reason why dilution refrigeration technology is so difficult to overcome is that if it wants to achieve an extremely low temperature environment, it means that helium, which is extremely amazing liquefaction technology in its natural state, is then achieved to the extreme, and as we all know, in the ordinary state, helium can become liquid, and when the temperature continues to drop, helium will have some very special properties.
3. Analysis of dilution refrigeration technology.
In ultra-low temperature environment, helium 3 and helium 4 will have a very special phenomenon, they will be stratified like oil and water, but will not be separated like oil and water, but will form a special mixed liquid state, this is mainly because at extremely low temperatures, helium 3 molecules will be more active than helium 4, resulting in a "viscous force" between them, although the two helium are mixed together, but not in the real sense of "mixing", but a "dissolution".
When we further cool the mixture of helium-3 and helium-4 in an extremely low temperature environment, then these heliums will form a unique liquid state, they will be in the same container, showing two different states, helium-3 will form a very dense layer of "liquid", and helium-4 will form a relatively thin layer of "liquid", and the liquid of helium-3 will float on the top, and the liquid of helium-4 will sink at the bottom, this special stratification phenomenon is very easy to make people think of "oil" and "water", two incompatible liquids.
However, helium-3 and helium-4 are not "completely separated", but there are some "interspersed" situations, that is, we can only "roughly separate" them, but cannot achieve "complete separation", which is one of the reasons why this special dilution refrigeration technology is superior to other technologies.
If you want to separate helium-3 and helium-4 completely, not just "roughly separate", then you need to continue to lower the temperature to make the difference between the two more obvious, but when the temperature is too low, it will cause the two deuterium gases to not solidify in the normal state, so how can they be "completely separated"?
This requires a very special and complex technology, that is, to "break" the current "incompatible" situation by changing the external environment, so as to achieve the effect of "complete separation", and this technology is what we call "dilution refrigeration technology".
The author thinks. Dilution refrigeration technology is a superb science and technology, which can provide human beings with a very low temperature environment, allowing us to discover some unprecedented scientific phenomena in this environment, enrich our scientific knowledge, and is also of great significance for the development of quantum technology.
We have also encountered many difficulties and challenges on the road to the development of dilution refrigeration technology, but Chinese scientists have always been moving forward, overcoming various technical difficulties, manufacturing the world's leading dilution refrigeration equipment, and making important contributions to the research and development of quantum computers.