A quantum computer processor with 105 qubits that Google unveiled at the end of 2024. Willow made headlines with the claim that it could perform a calculation in five minutes that would take a supercomputer 10 septillion years. However, the random circuit sampling (RCS) problem that was solved is known to be one that emphasizes huge differences between classical and quantum computing.
Advanced Error Correction
The key to Willow's amazing results is its error correction, which keeps the qubits stable for a longer period of time. This is known as "quantum coherence," and as a result, the machine can handle calculations with greater complexity. By reducing noise levels and making other enhancements, Google bumped quantum coherence time from 20 microseconds (µs) in its Sycamore quantum computer in 2019 to 100 µs in Willow five years later. See
Google quantum chips,
quantum computing and
quantum coherence.