Historic achievement – Accuracy of silicon-based quantum computers exceeds 99 percent

Historic achievement – Accuracy of silicon-based quantum computers exceeds 99 percent

We have reached a major milestone in quantum computing.

With silicon-based quantum computers, three separate groups in different parts of the world have crossed the 99 percent accuracy threshold.

The Australian team, led by New South Wales University physicist Andrea Morello, achieved 99.5 percent accuracy in single-bit operations and 99.37 percent accuracy in two-bit operations in three-bit systems.

The team in the Netherlands, led by physicist at the Delphi University of Technology Seigo Tarucha, achieved 99.87 percent accuracy in single-bit operations and 99.65 percent accuracy in quantum dots in two-bit operations.

Finally, in Japan, a team of researchers led by RIKEN physicist Akito Noir achieved 99.84 percent accuracy in single-bit operations and 99.51 percent accuracy in two-bit systems at quantum dots.

All three groups published the results in the journal Nature.

“Publications published in Nature show that our operations are 99 percent infallible. When mistakes are so rare, they can be fixed and corrected as soon as they occur. “It shows that it is possible to create quantum computers of sufficient scale, power and significant computation,” Morelio said.

Quantum computers are based on quantum mechanics as the basis of operations. Information is encrypted in qubits, or quantum bits, the equivalent of binary bits, or the basic unit of information for quantum computers.

However, where bits are processed in one of two states – 1 or 0 – qubits can be in both 1 and 0 states or both at the same time.

The latter state, 1 and 0 simultaneously, is called the superposition. Maintaining the superposition of the qubit allows quantum computers to solve complex mathematical problems because they perform calculations based on the probability of the state of an object rather than measuring it. The probability of errors in such attempts is high and the accuracy of quantum operations is the subject of strong research.

In 2014, Morello and his colleagues showed a 35-second duration of quantum information in a silicon substrate. Their qubits were based on the twisted state of the nuclei, which, in isolation from their own environment, allowed a new mark of time to be reached. But it was this isolation that turned out to be a problem: this made it difficult for the qubits to communicate with each other, which is essential for quantum computing.

To solve this problem, Morello and his group introduced electrons into the two-nucleus phosphor system by inserting ions into silicon; This process is one of the fundamental ones in the production of microchips. That’s how they created the three-bit system that worked.

“If you have two nuclei connected to the same electron, you can force them to perform quantum operations. When you do not process an electron, these nuclei safely store their own quantum information. “But now we can force them to communicate with each other electronically to perform universal quantum operations that can be adapted to any computational problem,” said Matthew Madzik, a physicist at the University of New South Wales.

The other two groups chose a different approach. They created quantum dots of silicon and silicon-germanium alloys and installed a two-electron gate; Or a circle of several qubits. Then, to characterize the systems, the voltage across the respective systems was changed to a protocol called gate set tomography.

Systems in both groups achieved more than 99 percent accuracy.

“This study shows that silicon-based quantum computers are promising candidates on the road to large-scale quantum computers,” said Seigo Tarucha.

Any separate research from these three is already a significant achievement. The fact that all three groups independently crossed the same, crucial stage, only indicates that a boom in quantum computing systems will soon begin.

“As a rule, an error rate of less than one percent is required to adapt to the quantum error correction protocol. Now that we have achieved this goal, we can start creating silicon quantum processors.