Google has issued a blog in which the company claims that its “Willow” quantum chip has achieved the first-ever demonstration of verifiable quantum advantage.
“This milestone is a critical step toward realizing useful quantum computation, a feat made possible by the precision and speed engineered into our quantum hardware systems,” stated Yu Chen, director, quantum processor, Google Quantum AI and Michel Devoret, chief scientist, Quantum Hardware, Google Quantum AI. They added that they “…set out to demonstrate its power in a complex, practical application, to take quantum computing closer to delivering real-world benefits.”
According to Chen and Devoret, they set out to reveal hidden information about the inner dynamics of quantum systems, such as molecules. In so doing, they “successfully executed” the highly complex Quantum Echoes algorithm, which relies on reversing the flow of quantum data in quantum computers, which in turn places strong demands on Willow’s performance at the system scale.
“It requires running the Willow chip with a large set of quantum gates and a high volume of quantum measurements — two key elements required to distill useful signals from background noise,” they said.
Willow’s quantum gates enabled the chip to perform the Quantum Echoes algorithms, involving large-scale quantum interferences and entanglement. “It concretely placed our results in a regime beyond the capabilities of classical computers,” according to the two researchers.
They said the chip features fidelities of 99.97 percent for single-qubit gates, 99.88 percent for entangling gates, and 99.5 percent for readout, all operating at a speed of tens to hundreds of nanoseconds across its entire 105-qubit array.
“…. this precision is matched by the fact that our system can perform millions of Quantum Echoes measurements in just tens of seconds,” they said. “This speed was instrumental in enabling a staggering one trillion measurements over the course of this project—a significant portion of all measurements ever performed on all quantum computers combined. This solidifies our work as one of the most complex experiments in the history of quantum computing. This solidifies our work as one of the most complex experiments in the history of quantum computing.”
Willow is built from superconducting quantum circuits. This field of research began with the discovery of the macroscopic quantum effect in 1985, an achievement that earned Devoret, John Clarke and John Martinis the status of 2025 Physics Nobel Laureates, the authors said. Utilizing these circuits, superconducting qubits function as macroscopic “artificial atoms.”
Chen and Devore said Willow’s qubits have demonstrated “an excellent balance of performance and scalability. This makes them a leading platform for building a fault-tolerant quantum computer.”
“As we march toward our next milestone — a long-lived logical qubit — we are fully aware of the numerous challenges ahead. Reaching our ultimate goal will require orders-of-magnitude improvement in system performance and scale, with millions of components to be developed and matured. Despite these hurdles, we remain committed to navigating this path forward.”
