Chinese researchers have taken a major step in the global race to build practical quantum computers, becoming the first team outside the United States – and the second in the world after Google – to cross a key threshold that determines whether these machines can work reliably at scale. A team led by Pan Jianwei at the University of Science and Technology of China said their superconducting quantum computer, Zuchongzhi 3.2, had reached the fault-tolerant threshold – a point where fixing errors...