Google Claims Quantum Advantage with Willow Chip

Google today claimed that its Willow quantum chip has achieved quantum advantage over a classic supercomputer by successfully running a quantum algorithm 13,000 times faster than a classical algorithm on the fastest classical supercomputer. If it pans out, this would be the first time a quantum computer has achieved quantum advantage. Google, which published its proof in the journal Nature, says that its experiment shows that the out-of-order time correlator (OTOC) algorithm, which it calls Quantum Echoes, ran 13,000 times faster on Willow than the best classical algorithm on one of the world’s fastest supercomputers. “This is the first time in history that any quantum computer has successfully run a verifiable algorithm that surpasses the ability of supercomputers,” wrote Hartmut Neven, the founder and lead of Google Quantum AI, and Vadim Smelyanskiy, the director of quantum pathfinding at Google Quantum AI, in a blog post today. Google’s Willow quantum chip “Quantum verifiability means the result can be repeated on our quantum computer–or any other of the same caliber–to get the same answer, confirming the result,” they continued. “This repeatable, beyond-classical computation is the basis for scalable verification, bringing quantum computers closer to becoming tools for practical applications.” Google Willow is a superconducting quantum chip that Google launched in December 2024. The chip uses 105 superconducting transmon qubits to perform quantum calculations. When Google launched the chip, it claimed that Willow had completed an error correction task in five minutes that it would have taken the world’s fastest supercomputer 10 septillion years. There are two milestones in the development of quantum computers that researchers and practitioners are on the lookout for. The first is dubbed quantum advantage, which is when a quantum computer solves a practical problem faster or more accurately than any classical computer ever could. The best estimates of industry observers held that we were likely still several years away from achieving quantum advantage, but they may need to reevaluate their assumptions after this announcement from Google. The second milestone, quantum supremacy, is arguably more important, as it marks the point at which a quantum computer demonstrates that it can solve problems that are impossible for classic computers to solve in a reasonable amount of time. We are still many years away from achieving quantum supremacy, industry observers note. Google CEO Sundar Pichai in front of a quantum computer The Quantum Echoes experiment works like a highly advanced echo. “We send a carefully crafted signal into our quantum system (qubits on Willow chip), perturb one qubit, then precisely reverse the signal’s evolution to listen for the ‘echo’ that comes back,” Neven and Smelyanskiy wrote. “This quantum echo is special because it gets amplified by constructive interference — a phenomenon where quantum waves add up to become stronger. This makes our measurement incredibly sensitive.” Google published its research on Quantum Echoes and Willow in a Nature article titled “Observation of constructive interference at the edge of quantum ergodicity.” The company is planning to post a pre-print copy of a second paper, titled “Quantum computation of molecular geometry via many-body nuclear spin echoes,” to arXiv later today. The second paper describes a proof-of-principle experiment it performed in partnership with the University of California, Berkeley. The groups ran the Quantum Echoes algorithm on Willow to study two molecules, one with 15 atoms and another with 28 atoms. “The results on our quantum computer matched those of traditional NMR [nuclear magnetic resonance], and revealed information not usually available from NMR, which is a crucial validation of our approach,” Neven and Smelyanskiy wrote. QC-enhanced NMR could become a powerful tool in drug discovery by helping to determine how potential medicines bind to their targets, or in materials science for characterizing the molecular structure of new materials, such as polymers, battery components, or even other quantum bits, the authors wrote. “This demonstration of the first-ever verifiable quantum advantage with our Quantum Echoes algorithm marks a significant step toward the first real-world applications of quantum computing,” Neven and Smelyanskiy wrote. “As we scale up towards a full-scale, error-corrected quantum computer, we expect many more such useful real-world applications to be invented. Now, we’re focused on achieving Milestone 3 on our quantum hardware roadmap, a long-lived logical qubit.” Below, you can watch Google’s video on Willow achieving quantum advantage.