https://www.vice.com/en_us/article/9kedqd/ok-wtf-is-google-quantum-supremacy

Last week, an historic claim from Google was accidentally (and briefly) posted online: its AI Quantum research group had achieved “quantum supremacy,” an important step towards ultra-powerful computers that can solve problems deemed impossible for current machines by using quantum physics.

The big reveal was somewhat thwarted by contributing researchers at NASA, who accidentally made a draft paper available. Not prone to understating its successes, Google made its bold assertion in the title of its research paper: “Quantum supremacy using a programmable superconducting processor.” Though the paper was quickly taken down, copies of it were archived and are floating around the web.