Software Google announces performance leap in quantum computing
According to Google, it has taken a decisive step towards overcoming one of the biggest challenges in quantum computing. The error rates have been significantly reduced.
09.12.2024, 18:07
SDA
The new special chip "Willow" and a new application method have paved the way for the development of practically usable quantum computers, said German computer scientist Hartmut Neven, founder and head of Google's Quantum Artificial Intelligence Laboratory.
Error rates below the threshold
In the scientific journal "Nature", Neven and his team report that quantum error correction with error rates below a relevant threshold has been achieved for the first time. Error correction is crucial for the development of scalable and applicable quantum computers.
Quantum computers can solve mathematical problems much faster than previous computers, for example when encrypting data, in materials research or in machine learning for artificial intelligence applications. However, the systems already developed are too small and make too many mistakes to deliver added value. Another problem is that the error rate increases with additional computing units ("qubits").
Bundling the computing units
To get to grips with this problem, the Google team combined several error-prone physical qubits into one less error-prone logical qubit. To demonstrate this connection, the researchers used the newly developed quantum processor "Willow".
Neven and his team emphasize that scalable, error-corrected quantum computers are possible with the method used and the new chip. However, the researchers also note that the error rate achieved is still not sufficient for an applicable quantum computer.
The team reckons that they would need significantly more physical qubits to achieve satisfactory rates. The use of more qubits with the method used will also lead to a longer computing time.
"Work meets high standards"
Markus Müller, Professor of Theoretical Quantum Technology at the Rheinisch-Westfälische Technische Hochschule Aachen (RWTH), explained that the Google team had succeeded for the first time in experimentally demonstrating quantum error correction well below the critical error thresholds and with a method that is scalable in principle. "The workers methodically meet the usual high standards in the research field."
Michael Hartmann, Professor of Theoretical Physics at Friedrich-Alexander-Universität Erlangen-Nürnberg, also praised the scientific quality of the work. "The given outlook is not unfounded." However, it should be noted that the authors made error-tolerant computing conditional on the results being scaled to significantly larger qubit numbers.
"Still a long way to go"
"With the current quality of qubits, 100,000 to one million qubits will be needed to perform large, fault-tolerant calculations that are beyond the reach of conventional supercomputers," Hartmann wrote in the Science Media Center (SMC). This paper presents the results of a chip with 105 qubits. "This shows how far we still have to go."
