Certified randomness using a trapped-ion quantum processor

In recent years, numerous theoretical results have shown evidence that quantum computers have the potential to tackle a wide range of problems out of reach of classical techniques. The main examples include factoring large integers6, implicitly solving exponentially sized systems of linear equations7, optimizing intractable problems8, learning certain functions9 and simulating large quantum many-body systems10. However, accounting for considerations such as quantum error correction overheads and gate speeds, the resource requirements of known quantum algorithms for these problems put them far outside the reach of near-term quantum devices, including many suggested fault-tolerant architectures. Consequently, it is unclear whether the devices available in the near term can benefit a practical application11. Starting with one of the first ‘quantum supremacy’ demonstrations5, several groups have used random circuit sampling (RCS) as an example of a task that can be executed faster and wit ... Read full article.