A team of Chinese researchers has announced the development of a quantum computer that took minutes to complete a calculation that would have taken a supercomputer 2 billion years. The team includes researchers from the University of Science and Technology of China, the Chinese Academy of Science, and the Tsinghua University. Last year, Google announced a quantum computer completing in minutes a calculation which would have taken a supercomputer 10 000 years. According to Chinese news agency Xinhuanet, the new quantum computer prototype processes 10 billion times faster than Google's quantum computer. As explained by Wired, the two systems work differently: Google used super-cold, superconducting metal, while the Chinese team manipulated photons (particles of light). One difference between the two is that the photonic prototype is not easily reprogrammable to run different calculations. Although at the moment quantum computers cannot perform useful work, the Chinese breakthrough is presented by its developers as a necessary step towards a large-scale, fault-tolerant quantum computer. It is also said to have potential practical applications in graph theory, quantum chemistry, and machine learning.