Google released Willow, its latest quantum chip. Google boasts that Willow performs state-of-the-art across several metrics, enabling two major achievements.
In the journal Nature, Google unveiled results demonstrating that increasing the number of qubits in Willow significantly reduces errors, bringing the system closer to true quantum behavior. They tested progressively larger arrays of physical qubits, scaling from a 3×3 grid of encoded qubits to a 5×5 and then a 7×7 grid. With each step, leveraging their latest advancements in quantum error correction, we were able to halve the error rate, achieving an exponential reduction. This milestone, known as “below threshold,” marks a critical breakthrough in quantum error correction. To make real progress in error correction, it’s essential to demonstrate the ability to reduce errors while scaling qubits, a challenge first posed by Peter Shor in 1995.
“The Willow chip is a major step on a journey that began over 10 years ago,” said Hartmut Neven, Founder and Lead, Google Quantum AI in a log post. “When I founded Google Quantum AI in 2012, the vision was to build a useful, large-scale quantum computer that could harness quantum mechanics — the “operating system” of nature to the extent we know it today — to benefit society by advancing scientific discovery, developing helpful applications, and tackling some of society’s greatest challenges. As part of Google Research, our team has charted a long-term roadmap, and Willow moves us significantly along that path towards commercially relevant applications.”
To assess Willow’s performance, Google used the Random Circuit Sampling (RCS) benchmark. Developed by its team and now a widely adopted standard in the field, RCS is currently the most challenging benchmark for a quantum computer to perform. It serves as a critical entry point for quantum computing, determining whether a quantum system can do something beyond the capabilities of classical computers. Any team working on quantum computers should first test if their system can outperform classical computers on RCS; if not, there is significant doubt about its ability to tackle more complex quantum tasks. Google has consistently used this benchmark to measure progress across different chip generations, reporting Sycamore results in October 2019 and again in October 2024.
“Willow’s performance on this benchmark is astonishing: It performed a computation in under five minutes that would take one of today’s fastest supercomputers 1025 or 10 septillion years,” said Google. “If you want to write it out, it’s 10,000,000,000,000,000,000,000,000 years. This mind-boggling number exceeds known timescales in physics and vastly exceeds the age of the universe. It lends credence to the notion that quantum computation occurs in many parallel universes, in line with the idea that we live in a multiverse, a prediction first made by David Deutsch.”
