“A paper by Google’s researchers seen by the FT, that was briefly posted earlier this week on a Nasa website before being removed, claimed that their processor was able to perform a calculation in three minutes and 20 seconds that would take today’s most advanced classical computer, known as Summit, approximately 10,000 years. The researchers said this meant the “quantum supremacy”, when quantum computers carry out calculations that had previously been impossible, had been achieved.”
Source : Google claims to have reached quantum supremacy | Financial Times