In a breakthrough that pushes quantum computing beyond theory toward proof, Google Research has announced the development of a new algorithm capable of verifiably outperforming classical supercomputers.

This demonstrates for the first time that a quantum processor can complete a calculation that would take existing computers decades while allowing researchers to mathematically verify that the result is correct.

The achievement, described in a paper released this week and in a Google Research blog post detailing the development, is an experiment built around Quantum Echoes, a method Google designed to test and confirm the performance of its quantum chip, Willow. Using a physics concept known as the out-of-time ordered correlator (OTOC), the team was able to measure how information spreads within a quantum system and, crucially, was able to reverse it. In creating this quantum echo, Google proved that Willow could both perform and verify the computation.

“This is the first time in history that any quantum computer has successfully run a verifiable algorithm that surpasses the ability of supercomputers,” Google stated in its blog post detailing the breakthrough. “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. This repeatable, beyond-classical computation is the basis for scalable verification, bringing quantum computers closer to becoming tools for practical applications.”

This is a big deal for Google, which was criticized in 2019 for claiming “quantum supremacy” when its earlier Sycamore processor completed a narrow task faster than any other supercomputer, but the result was not verifiable. With Quantum Echoes, verification is now built in, allowing researchers to use mathematical proofs to confirm that the results are genuine rather than statistical artifacts or noise.

Why this matters

Quantum computers use qubits instead of the standard bits found in regular computers. Qubits can be both 0 and 1 at the same time, allowing quantum systems to test many possibilities at once. The problem is that qubits are fragile, and anything from heat to noise can cause them to lose their state. Keeping them stable long enough to finish a calculation remains one of the biggest challenges in the field.

Willow’s Quantum Echoes experiment shows that these fragile quantum systems can now perform complex, verifiable operations that are far beyond what traditional computers can handle. According to Google, the same task would take the fastest-known classical system an estimated 47 years to complete, while Willow completed it in minutes.

If verified, this progress could accelerate breakthroughs across many sectors, especially science and technology. Quantum processors capable of dependable, verifiable performance could make it possible to simulate molecular interactions for new medicines, model complex materials for cleaner energy, and optimize global logistics or financial systems beyond today’s computational limitations.

A new phase for quantum computing

While exciting, Google’s breakthrough does not mean quantum computing is ready for everyday use. The technology still faces formidable challenges, including scaling to thousands of reliable qubits, reducing error rates, and maintaining quantum states at near-absolute-zero temperatures.

Even so, this achievement changes the conversation. It establishes a benchmark for what “verifiable quantum advantage” looks like, which now includes built-in mathematical proof.

For now, Google’s work shows that quantum computing has entered a new phase in which performance can be measured, confirmed, and trusted. In a field plagued by uncertainty, this may be its most significant advance yet.

The UK’s Competition and Markets Authority has confirmed that Google (and Apple) hold “strategic market status” in their mobile platforms, a move that gives the regulator broad powers to address potential competition concerns.