Google Willow: First Verifiable Quantum Advantage
In October 2025, Google demonstrated the first verifiable quantum advantage using the Willow chip. Running the Quantum Echoes algorithm (based on out-of-time-order correlators, OTOC) on 65 qubits, Willow completed the computation approximately 13,000 times faster than the world's best classical supercomputer.
The key distinction from prior quantum supremacy claims (e.g., 2019 Sycamore RCS): Quantum Echoes results can be independently verified by other quantum computers or physical experiments — not just estimated. This directly addresses the longstanding criticism that earlier supremacy demonstrations used tasks with no independent verification method.
This milestone signals a fundamental transition: from 'quantum supremacy' (hard-to-verify speed records on artificial benchmarks) to 'quantum advantage' (verified computational superiority on tasks with independent cross-check). It closes a critical credibility gap in quantum computing research.