Researchers in China have claimed to have achieved quantum supremacy, building a quantum computer capable of carrying out calculations trillions of times faster than today’s most powerful supercomputers.
According to a paper published in the journal Science on Thursday, the computer, developed by a team of scientists at the University of Science and Technology of China in central Hefei, completed a calculation almost 100tn times quicker than existing supercomputers.
The breakthrough comes a year after Google proclaimed itself the first to reach the milestone with its Sycamore machine.
According to Lu Chaoyang, a professor in charge of the experiment at USTC, the Chinese computer achieved the breakthrough by manipulating particles of light. This contrasts with Google’s supercomputer, which relied on ultra-cold superconducting chips.
Christine Silberhorn, an expert in quantum optics at Paderborn University in Germany, called the Chinese team’s work a “milestone experiment”.
While the use of quantum machines to solve practical problems is still years away, the emerging field is hotly contested, with the US and China racing to gain advantages in areas such as encryption and complex problem-solving.
In 2017 Ms Silberhorn was one of the co-developers of the technique known as “Gaussian boson sampling”, which the Chinese team built on with their machine. “The concepts used were in the literature, but this experiment demonstrates the scaling, which is a crucial step,” she said.
China’s official news agency Xinhua claimed the computer, which comprises lasers, mirrors, prisms and photon detectors, could process 10bn times faster than the quantum computer unveiled by Google last year. Google did not immediately respond to a request for comment.
Mr Lu said he admired Google’s work. “Building a quantum computer is a race between humans and nature, not between countries,” he said, adding that so far the “quantum machine can only do a specific job, not all jobs. It is not fully programmable yet. This is something we are working on.”
If they can be built at scale, quantum computers will harness properties that extend beyond the limits of classical physics to offer exponential gains in computing power.
“Scientists are close to useful quantum machines that can do something non-trivial,” Mr Lu added.
Richard Murray, chief executive of London-based quantum computing company ORCA, said the news was encouraging for the whole industry.
“There are still people who question whether quantum computers will be a reality,” he said. “With two systems having achieved this benchmark, that argument is sounding quite unlikely.”
Additional reporting by Nian Liu in Beijing