Google’s Willow Quantum Processor

In October, 2025, Google announced that its quantum processor Willow has achieved the first “verifiable” quantum advantage — proving that a quantum computer can outperform the most advanced classical supercomputers in practice.

Key Points

Historic Achievement: Google’s Quantum AI team, in collaboration with researchers, published an open-access paper demonstrating Willow’s ability to complete quantum algorithms exponentially faster than traditional computers.
Quantum Echoes Algorithm: Willow executed a novel algorithm named Quantum Echoes, performing calculations 13,000 times faster than the best classical algorithm on one of the world’s fastest supercomputers.
Scientific Basis – OTOC Measurement: The study centered on a quantum measurement technique called out-of-time-order correlator (OTOC), which tracks how information spreads and gets scrambled inside a quantum system, offering a window into quantum chaos and order.
Building a Quantum ‘Time Machine’: Researchers used Willow’s superconducting qubits to simulate a chaotic quantum system and then reversed its evolution twice, using a second-order OTOC to observe how information retraced its path — a process likened to rewinding and replaying time.
Proof of Quantum Interference: The team inserted random operations midway through the experiment, proving that the observed signals were driven by true quantum interference — waves combining constructively and destructively, rather than random probabilistic outcomes.