The first quantum circuit laid the foundation for a computing revolution

This first atomic-scale quantum integrated circuit represents an important step in the development of quantum computing that is useful in real-world conditions.

Australian researchers recently announced the creation of what they describe as “first quantum integrated circuit made at atomic scalee “; they have proven to be successful in adapting all the elements required for the operation of a computer of this class on a chip with a standard format.

And this circuit can even function as a full -fledged quantum processor. This allowed researchers to mimic the movement of electrons in a small molecule, polyacetylene. This has an advantage that is well known to researchers. The latter can immediately determine the consistency of the result, and by extending the reliability of the chip.

And at the end of the test protocol, the result was clear: the circuit showed surprising accuracy during the simulations. According to the researchers, this is enough to “certainly proves the validity of this technology in the context of quantum modeling systems”.

This work published in the prestigious journal Nature is very exciting. This is a real proof of concept that will undoubtedly bring us closer to the democratization of quantum computers, even if this deadline is still far away.

From a simple “transistor” to a real circuit

This circuit was the first demonstration of a long series of works that began in 2012. At the time, quantum computing was more in its infancy than it is today. These same researchers recently created the very first “quantum transistor”.

Transistors are small electronic components based on semiconductor materials – those with a lack of burning technology for months. In very short, they act like little 100% electronic switches; so they are basic elements of all logic circuits because they support the famous “bits”.

It is therefore an important standard of technology for all modern computers. It’s a technology that is now very well mastered, and manufacturers are making real feats when it comes to miniaturizing these components. But this is a different story when it comes to applying this concept to quantum computing, where everything is played out on the scale of infinitely small.

People are very good at making microscopic components… © Umberto – Unsplash

An ultra-demanding manufacturing process

To build their chip, they had to use a transmission electron microscope capable of detecting atomic-scale detail. They have to do the whole process in almost complete vacuum, because at this scale, even one oxygen atom can be a problem.

These are very important constraints that are sadly impossible to avoid in order to achieve the desired level of accuracy on the final chip. It allows researchers to sort multiple quantum dots, better known as quantum dots (QDs). A name that is sure to ring a bell for fans of display technology.

Concretely, these QDs are structures based on semiconductor materials, like the transistors in today’s computers. On the other hand, these measurements are only a few nanometers. So they can behave like quantum transistors once arranged with extreme precision. So they can serve as pixels on some high-end OLED screens. Like standard transistors that are home bits, these quantum dots can also serve as carriers of qubits, the basic unit of quantum computing.

But to this extent, permits are almost non -existent. Researchers need to know the exact number of phosphorus atoms needed in each QD. They need to know the position of each point, then arrange it on the chip with an accuracy of less than a nanometer and a margin of error of almost zero.

If they are too large or too close, the interactions between the points can be very powerful; it may be impossible to control them individually. Conversely, if they are too small or too far apart, these interactions may be unpredictable. In both cases, this will damage the functioning of the chip.

… But everything can be more complicated when working on the scale of elementary particles. © Norbert Kowalczyk

The beginning of a real paradigm shift?

Not surprisingly, the researchers therefore needed a lot of replacements to build their chip; they put 10 QDs there. It therefore represents a lot of effort for a circuit that, in the end, remains weak despite its accuracy. In fact, these 10 qubits are not enough to use in real situations.

But the interest in this work is more in the method than in the final product. By opening the door to making real quantum chips, we can begin to look at the first practical and relatively “mainstream” applications (everything considered) of this technology.

Because at present, the practical interest of these machines is still very limited; they are primarily exploratory tools that are never used to do concrete work. In addition, quantum computers are currently reserved for institutions with multiple technological and financial resources.

Eventually, chips of this kind could serve as a vector to break it exclusively and democratize quantum computing. The obstacles are still many; to begin, it is necessary to make a circuit more powerfuland able to operate at room temperature.

Technically, IBM’s Q System One was the first circuit -based quantum computer; but his chip is not yet self -sufficient, contrary to the proof of concept by Australian researchers. © IBM Research

In fact, in order to work, current quantum computers must maintain a temperature close to absolute zero. So the challenge is to find a way to overcome this constraint; but so far, no one has found the slightest sign of this direction. And this is just an isolated example amidst a mountain of limitations (see our articles here, here and here) that still hinder the development of quantum computing.

So it is not tomorrow that this technology will become commonplace. But it cannot be denied that this is an important step in this direction. In traditional computing, the first transistor shows up 1947the first integrated circuit in 1958and the first personal computers in years 1970. If quantum computing follows a comparable trajectory (which is anything but a guarantee), the long -awaited computing revolution could come. for several decades.

The text of the study is here.

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