We talk about the prerequisites and give the opinions of experts.
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Why is helium needed in quantum computers
Before moving on to the story of the helium shortage situation, let's talk about why quantum computers need helium at all.
Quantum machines operate on qubits. They, unlike classical bits, can be in states 0 and 1 at the same time - in superposition. In a computing system, the phenomenon of quantum parallelism arises, when operations are performed simultaneously with zero and one. This feature allows machines based on qubits to solve some problems faster than classical computers - for example, to simulate molecular and chemical reactions.
But there is a problem here: qubits are fragile objects and they can maintain superposition for only a few nanoseconds. It is violated even by a slight temperature fluctuation, the so-called . To avoid destroying qubits, quantum computers at low temperatures - 10 mK (-273,14Β°C). To achieve temperatures close to absolute zero, companies use liquid helium, or rather, an isotope , which does not harden under such extreme conditions.
What is the problem
In the near future, the IT industry may face a shortage of helium-3 for the development of quantum computers. On Earth, this substance is practically not found in its natural form - its volume in the atmosphere of the planet (1,37 ppm relative to helium-4). Helium-3 is a decay product of tritium, the production of which (the last heavy-water nuclear reactor was closed in the USA). After tritium began to be mined from the components of decommissioned nuclear weapons, but according to Congressional Research Service, this initiative did not significantly increase the stocks of the strategic substance. Russia and the US have some reserves, but .
The situation is aggravated by the fact that a fairly significant part of the helium-3 goes into the production of neutron scanners used at border points to search for radioactive materials. The neutron scanner has been a mandatory tool at all US customs since 2000. Due to a number of these factors in the United States, helium-3 supplies are already controlled by government agencies that issue quotas to public and private organizations, and IT experts worry that there will soon be not enough helium-3 for everyone.
How bad it is
There is an opinion that the lack of helium-3 will have a negative impact on quantum development. Blake Johnson, vice president of quantum computer manufacturer Rigetti Computing, in an interview with MIT Tech Review that refrigerant is incredibly hard to come by. The problems are exacerbated by its high cost - it takes $40 to fill one refrigeration unit.
But representatives of D-Wave, another quantum startup, disagree with Blake's opinion. By vice president of the organization, the production of one quantum computer takes only a small amount of helium-3, which can be called negligible compared to the total amount of material available. Therefore, the shortage of refrigerant will be invisible to the quantum industry.
Plus, other methods of helium-3 production that are not related to tritium are being worked out today. One of them is the extraction of an isotope from natural gas. First, it undergoes deep condensation at low temperatures, and then passes through the processes of separation and rectification (separation of gas impurities). Previously, this approach was considered economically inexpedient, but with the development of technology, the situation has changed. Last year about his plans to start mining helium-3 .
A number of countries are making plans to mine helium-3 on the moon. Its surface layer contains up to (tab. 2) of this substance. According to scientists, the resource will last for five millennia. NASA has already begun to create who process into helium-3. The development of the corresponding terrestrial and lunar infrastructure is carried out by ΠΈ . But it will not be possible to implement it in practice until 2030.
Another way to prevent a shortage of helium-3 is to find a replacement for it in the production of neutron scanners. By the way, her in 2018, it was crystals of zinc sulfide and lithium-6 fluoride. They allow you to register radioactive materials with an accuracy exceeding 90%.
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Other "quantum" problems
In addition to the shortage of helium, there are other difficulties that hinder the development of quantum computers. The first is the lack of hardware components. There are still few large enterprises in the world involved in the development of "stuffing" for quantum machines. Sometimes companies have to wait until the cooling system is manufactured, .
A number of countries are trying to solve the problem through government programs. Such initiatives have already been launched in the US and Europe. For example, recently in the Netherlands, with the support of the Ministry of Economy, Delft Circuits started operating. It is engaged in the production of components for quantum computing systems.
Another difficulty is the lack of specialists. Demand for them is growing, but finding them is not so easy. By NYT, there are no more than a thousand experienced "quantum engineers" in the world. The problem is solved by the leading technical universities. For example, at MIT already the first programs for training specialists in working with quantum machines. Development of relevant academic programs and in the American National Quantum Initiative.
In general, IT experts are convinced that the problems facing the creators of quantum computers are quite surmountable. And in the future, we can expect new technological breakthroughs in this area.
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Source: habr.com