For the first time, researchers have proven that a quantum computer can execute a verifiable algorithm faster than any classical supercomputer. This breakthrough, achieved using Google’s Willow quantum processor, represents a big step toward practical, real-world applications of quantum computing: in fields ranging from drug discovery to materials science.
Team innovation focuses on A new algorithm called quantum echoesAble to explore the hidden structure of nature with unprecedented precision. Just like how sonar sends a signal into the ocean and listens to the echo to reveal what lies beneath, quantum echoes send a quantum signal to a system of particles, perturb it, and then reverse time to capture an “echo” that reveals complex quantum behavior.
This echo is not an ordinary reflection. Thanks to a phenomenon called constructive interference, quantum waves amplify each other, producing highly sensitive measurements that reveal the structure of molecules, and even shed light on underlying systems such as magnets or black holes.
Running on the Willow chip, the Quantum Echoes algorithm achieved a calculation 13,000 times faster than what could be achieved on Frontier – the world’s most powerful classical supercomputer. In one test, the system simulated the geometry of molecules containing up to 28 atoms, matching and even exceeding the results of traditional nuclear magnetic resonance methods used in chemistry.
This represents the first verifiable quantum feature: a repeatable result that goes beyond classical and can be confirmed by another quantum computer of the same quality – a crucial step towards trustworthy and scalable quantum computation.
Behind this achievement lies deep theoretical work on out-of-time correlations (OTOCs) – exotic mathematical tools that reveal how information propagates in complex quantum systems. When the researchers applied repeated time-reversal protocols (essentially rewinding and restarting quantum dynamics), they discovered that second-order OTOCs (OTOC²) retained sensitivity to fundamental physics for much longer than expected.
These higher-order quantum echoes have not only revealed new insights into quantum interference, but have also reached a level of complexity that classical computers can no longer emulate efficiently. For example, simulating a 65-qubit experiment using a supercomputer could take more than three years, compared to just a few hours on a quantum processor.
Beyond theory, the research demonstrated a real-world application called Hamiltonian learning, which is a method of discovering the physical laws governing a system by comparing quantitatively measured data with quantum simulation models. In a proof-of-principle experiment, the team successfully identified an unknown factor in a simulated molecular system, paving the way for future applications in materials design and chemical analysis.
This achievement fulfills two of the three conditions that scientists have identified for achieving practical quantum advantage:
- The result can be measured accurately (with strong signal-to-noise ratio).
- It cannot be classically simulated using possible resources.
The third goal—deriving practically useful insights—is already on the horizon, with potential applications in solid physics, biochemistry, and energy research.
As quantum devices continue to mature, the implications are wide-ranging. The Quantum Echoes algorithm shows that we are moving beyond laboratory curiosities toward quantum computers that can take on meaningful scientific challenges, revealing the invisible patterns that shape our world.
