Scientists from China are again challenging Google’s claim to “quantum supremacy” after a research team said it had developed an algorithm to perform a task “thought to be impossible for classical computations”. The Chinese team said their non-quantum classical computer completed the sampling task “in about 15 hours” with higher estimated fidelity – or accuracy – than Google’s quantum computer Sycamore, which took 200 seconds for the same task. The team said the 1 million uncorrelated samples generated using their method had a fidelity of 0.0037, compared to that of the Google quantum computer’s 0.002. So-called quantum supremacy is a…