A team of researchers affiliated with several institutions in China has built and tested a photonic quantum computer that demonstrates quantum supremacy. In their paper published in the journal Science, the group describes their computer, which they call Jiuzhang, and how well it performed while conducting Gaussian boson sampling. The researchers found that it took Jiuzhang approximately 200 seconds to provide an answer. They noted that it would have taken the world’s fastest supercomputer approximately 2.5 billion years to carry out the same calculations, a clear example of quantum supremacy. https://phys.org/news/2020-12-chinese-photonic-quantum-supremacy.html
