On Thursday, Dec. 3, China's leading quantum research group made their declaration of "quantum supremacy" in a paper published in the journal Science. Here, they describe how their system, called "Jiuzhang" produced results in minutes calculated to take more than 2 billion years of effort by the world's third-most-powerful supercomputer.
The results from the Chinese team come about a year after Google won international acclaim for its prototype quantum computer "Sycamore," which completed within minutes a calculation that, its researchers estimated, would have taken a regular supercomputer 10,000 years. That moment met the definition of "quantum supremacy" – the moment a quantum computer does something impractical for a conventional one.
According to the Chinese team, based primarily at the University of Science and Technology of China in Hefei, their quantum computer is 10 billion times faster than Google's. Should their claim hold up, Jiuzhang would be the second quantum computer to achieve quantum supremacy.
The two systems work differently. Google's Sycamore uses supercold, superconducting metal. The Chinese team, on the other hand, built Jiuzhang to get its results by manipulating photons, particles of light.
No quantum computer is ready to do any actual useful work. But the results that show that two fundamentally different forms of quantum computing can outperform supercomputers will buoy the hopes – and investments – of those in the nascent industry. Chao-Yang Lu, one of the researchers at the project, said that their achievement was "a necessary step" towards the development of "large-scale fault-tolerant" quantum computers.
Several companies -- including IBM, Microsoft, Amazon, Intel and, of course, Google -- have all invested heavily into developing quantum computing hardware in recent years. Microsoft's and Amazon's cloud platforms each host various quantum hardware from companies such as Honeywell. Meanwhile, Google and IBM already provide access to their latest prototypes over the Internet.
Quantum computers' potential comes from their basic building blocks, called cubits. While the bits of conventional computers can only represent data as ones and zeros, qubits can use quantum mechanics to attain a state called superposition, where they encapsulate the possibilities of both. This allows quantum computers the possibility of taking computational shortcuts conventional computers can't. (Related: Quantum computer allows you to see "multiple futures.")
The reason quantum computers haven't taken off is that engineers have yet to get enough qubits working together reliably enough – the quantum mechanical effects they depend on are very delicate.
Despite this, the potential of quantum computers is clear to see, as such, China is investing heavily in the field. The Chinese government has spent $10 billion on the country's National Laboratory for Quantum Information Sciences.
In October, Chinese President Xi Jinping stressed the importance of strengthening the development of quantum science and technology at a group study session of the Chinese Communist Party's politburo. Xi called for efforts to make breakthroughs in the field to help enhance China's ability to respond to international risks and challenges with science and technology.
Observers at the session noted that China was putting more importance on technologies like quantum computing due to how uncertainties in global politics could threaten their access to such technologies.
With their latest breakthrough, it does seem that Chinese scientists are on their way to achieving what their country's leadership has set out for them.
The question now is if the companies involved in quantum computing in the West can regain the lead in the race to develop practical applications for the technology.
Follow Computing.news for more on quantum computers and other new developments in computing.