Google’s Willow chip runs quantum algorithm 13,000 times faster than supercomputers: here is how its superconducting design makes it possible

Google has announced a major breakthrough with its effort to achieve usable quantum computing. The company’s Willow processor reportedly executed a complex Quantum Echoes algorithm about 13,000 times faster than the current fastest classical supercomputers.

Willow represents a significant leap from Google’s breakthrough with the Sycamore chip in 2019. Unlike the latter, the former superconducting chip has real-world value. It has demonstrated application in AI development, chemical modelling, and advanced materials research, according to the results published in Nature.

How Google’s superconducting quantum chip works

The Willow chip employs 105 superconducting qubits (qubit is short for quantum bit, the basic unit of information in quantum computing; it is similar to the bit in classical computing). Each qubit functions as a mock atom and can house information in superposition or multiple states simultaneously.

When the qubits entangle (a state where two or more qubits have an effect on one another, no matter the distance between them), they pass quantum information in real time. This enables the processor to analyse multiple solutions simultaneously.

Quantum systems have to be stable to maintain a predictable relationship between their quantum states over time. Hence, Google designed Willow to operate at near absolute zero, keeping out heat and vibrational interference.

The chip’s architecture is optimized for speed and precision, and the experiment reported single-qubit gate fidelities of 99.97 percent and entangling gates at 99.88 percent. This makes Willow ideal for running large-scale quantum algorithms.

(Gate fidelity is a measure of how a quantum gate functions compared to its ideal, error-free version. The closer to 100 percent, the more it behaves like its theoretical model.)

How Google validated Willow’s quantum computing prowess

The Willow project is special because of its verifiability. Thanks to the ability of the Quantum Echoes algorithm’s results to be validated across different machines or laboratory conditions, Google was able to meet the key requirements for claiming quantum superiority.

The Quantum Echoes algorithm helps researchers to model molecular behaviour, chemical bonds, and electronic structures more accurately than classical simulations. The chip powered a supercomputer that solved the algorithm, delivering results in one-thirteenth-thousandth the time it would take a classical supercomputer.

As Google researcher Tom O’Brien said, Willow’s reproducibility is what separates theoretical and practical breakthroughs. He stated, “If we can’t prove the data is correct, we can’t do anything with it.”

Another researcher on the project, Nobel laureate Michel H. Devoret, who was the lead physicist, said, “We showed that electrical circuits can behave like atoms. Now we’re showing what those artificial atoms can do.”

What does Google’s Willow quantum computing breakthrough mean for AI and science?

The Willow superconductor chip can help reduce the time scientists need to simulate biological systems by a large magnitude. It also has the potential to handle scenarios where classical computing fails to generate accurate datasets.

Google’s processor can also be applied to new material designs and to training data-efficient AI systems. If further validated, the Willow breakthrough could bring quantum computation to the threshold of practicality and scalability in solving industrial problems.