How Russian scientists organized quantum races In 2023, the first 16-qubit quantum processor will be presented at the RCC

quantum race

Quantum technologies are a promising scientific direction, one of the goals of which is to create a quantum computer. Unlike a classical computer, a quantum computer uses qubits, not bits, for calculations. Qubits are quantum bits in superposition, meaning they can be in two states at once.

“It can be likened to flipping a coin: as long as it flies, it remains heads and tails for the shooter. This superposition continues until a coin is caught or a qubit is calculated. Thanks to this feature, calculations in quantum systems are performed faster than in classical ones, ”Gleb Fedorov, senior researcher at the MIPT Artificial Quantum Systems Laboratory, told socialbites.ca.

In Russia, as elsewhere in the world, scientists are trying to create a quantum computer, but everyone went their own way.

Thus, in 2022, MIPT physicists, together with their colleagues from NUST MISiS, demonstrated for the first time a fully functioning four-qubit quantum processor, on which high accuracy of operations is achieved using special precision (high precision) methods. approved. In 2021, employees of the Russian Quantum Center and FIAN have already presented a similar quantum processor, but on two trapped ions (quartz) at a meeting of the Scientific Council of the Russian Academy of Sciences.

According to RCC employees, scientists at that time were among the first in the world to create a processor based on two quarts – a multilevel quantum system entirely equivalent to four qubits. Scientific publication preprint seen On arXiv.org in October 2022. However, MIPT states that technical details confirming this in 2021 have not been presented.

Now a scientific group from the Moscow Institute of Physics and Technology and NUST MISiS is developing an 8-qubit system that they plan to present before the end of this year. It is planned to develop a system of 16 qubits by 2024. RCC and FIAN will introduce a new 16-qubit version of the processor next year.

“The superconducting systems we work with at MIPT are actually also multi-level quantum systems, but no one in the world uses them to encode a few qubits, because this involves significant technical difficulties: leakage to higher levels must be prevented. At the Laboratory of Artificial Quantum Systems at the Moscow Institute of Physics and Technology. “I think the situation is about the same with regard to the ions in the traps,” said senior researcher Alexei Dmitriev.

In addition to these scientific groups, a quantum processor is being developed at Moscow State University, in which scientists work, among other things, on atoms.

“In our case, the role of a physical qubit is played by an atom caught in a small laser trap (optical tweezers). The states of a qubit are encoded in the relative orientation of the spin of an electron and an atomic nucleus: either in the same way (1) or in the opposite direction (0 ) are directed,” explains Stanislav Straupe, head of the quantum computing industry at the Computer Science Center of Moscow State University.

According to Straupe, the research team is working on a 16-qubit processor that they plan to introduce officially next year.

What is better?

Although all systems may seem the same at first glance, they all have their pros and cons. For example, superconducting quantum systems allow quantum processors to be scaled up, that is, to increase the number of qubits in them. Currently, the largest number of fully controlled qubits has been reached precisely in superconducting processors – for example, IBM claims a fully controlled circuit with more than 400 qubits.

Atomic and ion quantum computers are also scalable due to the lack of chips. According to experts from the RCC and Moscow State University, this is easier to do.

“The number of superconducting systems in a circuit on a chip can be arbitrarily increased, there are no technical restrictions on this, moreover, it is possible to connect qubits on different chips or even different cryostats using special cryogenic bonds. On the other hand, the number of atoms captured by optical tweezers cannot be arbitrarily large, the capture area is limited by the focal point of the laser beam,” says Gleb Fedorov.

At the same time, Straupe pointed out that superconducting processors have an electrical circuit that sets the ceiling for the number of qubits.

“This number is absolutely constant. Our atoms live in optical traps, and the atomic number is determined by how many we can catch. It could be more, it could be less. It’s an easily reconfigurable model because it doesn’t have a chip, the atoms just hang in the air,” Straupe explained.

In addition, technologies have different lifetimes. The lifetime of quantum bits is the time the qubits stay in superposition. This is called “adaptation time”. The key role is played by the number of operations that can be performed during the consistency of the qubits. The larger this parameter, the greater the ability of the qubit to perform complex tasks.

So, for example, the lifetime of qubits in the processor, presented by employees of the Moscow Institute of Physics and Technology and NUST MISiS, is 20 microseconds, while individual operations take 10-15 nanoseconds. RCC and FIAN’s ion processor have up to 5 milliseconds, and Moscow State University has a few milliseconds too.

MIPT technology is by far the most accurate technology in Russia – the accuracy of calculations reaches 97%. By the end of 2022, MIPT scientists will produce and present an 8-qubit system. In 2023, the accuracy of operations will be increased to 99%.

“It is important to note that our accuracy results are already very close to the world level. It should also be emphasized that a large number of groups around the world have had similar results on different types of superconducting qubits, which confirms the high potential of this platform,” said Dmitriev.

Last year, the computational accuracy of RCC and FIAN’s 4-qubit ionic system was 70%.

“We hope to exceed the 90% accuracy threshold with the release of a new processor, but we can still lag behind our peers in this indicator,” said Ilya Semerikov, vice president of RCC Precision Quantum Measurements research group. .

The Moscow State University processor still can not keep up with its “colleagues” from MIPT. Straupe said the quality of operations is about 70%.

“We haven’t presented the processor yet as we’re working to improve accuracy – our goal is to reach 99.9%. Maybe we’ll introduce it next year. The problem is laser noise. Straupe said that a more powerful laser is needed to increase the number of qubits, but it’s still manufactured by the company.

Despite the differences in approaches, all scientific groups emphasize the importance of developing all options for the implementation of quantum systems. According to the scientists, this will allow them to keep up with their Western counterparts, who have significantly outstripped Russia in quantum developments.

Why do we need a quantum computer?

The development of quantum technologies will make it possible to solve many problems of modern computers more efficiently and quickly. For example, quantum computers can be used for ultra-fast database searches, computer simulations, factorization of numbers to crack encryption algorithms, and artificial intelligence quantum machine learning.

Additionally, a quantum computer could be used to calculate large organic molecules for drugs, create optimal car routes, or optimize an investment portfolio.

“A quantum computer will be able to do this much more efficiently and quickly than existing algorithms. The applications are huge, but so far all are speculative. There is no device yet. When it appears, people will find new tasks. It seems to me that even a 433-qubit IBM computer not enough. We need thousands of qubits,” Straupe said.

According to Semerikov, no one yet knows how to build a quantum computer powerful enough to perform all these tasks.

“This is what everyone is struggling with right now. Although we do not know when we will create such a computer, I do not dare to make any guesses about the timing of its invention, but it is certainly possible,” Semerikov emphasized.

According to experts, the lack of equipment can slow down the pace of development of the industry. Cryostats, lasers and lithographs are needed for work. Some of this equipment can be purchased from other countries, but today engineers and researchers are working on point local production.

“In Russia, this field of quantum technologies is less developed, it began to be actively studied only in 2015, and in the West 20 years ago. It is important to emphasize that in the US they are trying to increase the number of qubits, but we are trying to make operations more accurate, which is a little more important. It is difficult to say when we will catch up with our Western colleagues – maybe in 2030, or maybe in 2050, ”concluded Gleb Fedorov.