Willow: Google’s Quantum Leap into the Future of Computing
Today, I’ll talk about Google Quantum AI’s groundbreaking innovation: Willow. Willow is Google’s latest and most powerful superconducting quantum computing chip, marking a significant step toward building large-scale quantum computers and unlocking their revolutionary applications.
Julian Kelly, the Director of Hardware at Google Quantum AI, along with his team, introduced Willow. Julian has been involved in quantum computing since 2008, and seeing this vision become a reality has been an incredible journey for him.
Looking back, Google launched its first chip, Foxtail, in 2017. This was followed by Bristlecone in 2018 and the groundbreaking Sycamore in 2019, which became the first quantum computer to outperform a classical supercomputer in a computational task.
With Willow, Google has taken a giant leap forward. It has improved quantum coherence times fivefold, increasing from 20 microseconds in Sycamore to an impressive 100 microseconds in Willow—all without compromising the features that made its predecessors successful.
This achievement was made possible by Google’s new superconducting quantum chip fabrication facility in Santa Barbara, one of only a few such facilities in the world. The results from Willow are remarkable—it’s the first quantum computer to operate below the critical quantum error correction threshold, a long-standing goal in quantum computing since the 1990s.
Practically speaking, Willow’s performance is astonishing. It was tested against one of the world’s most powerful supercomputers using the random circuit sampling benchmark, and the results are incredible. A calculation that Willow completes in under five minutes would take the world’s fastest supercomputer 10 to 25 years.
This growing gap between classical and quantum computation for specific tasks is just the beginning. Google’s hardware approach, featuring tunable qubits and couplers, allows ultra-fast operations, on-the-fly hardware optimization, and high connectivity for efficient algorithm execution.
The team leverages this tunability to ensure consistent high performance. For instance, they can fix outlier qubits with unusually high error rates by reconfiguring them to align with the rest of the system. Researchers are continuously developing new calibration strategies to minimize errors across all qubits using advanced software.
The technical specifications of Willow are extraordinary. It features a large number of highly connected qubits, enabling diverse applications. It boasts low mean error rates, significantly extended coherence times, and extremely high measurement rates. Most importantly, it’s the first quantum computer to operate below the error correction threshold, setting it apart in the field.
Looking ahead, Google is excited to continue its journey toward building large-scale, error-corrected quantum computers that will redefine science and nature’s exploration. With potential applications in fields like pharmaceuticals, batteries, and fusion power, the possibilities are endless. Willow is just the beginning, paving the way to solve the unsolvable problems of tomorrow.
