An international collaborative study conducted by a team from Denmark, the United States, Canada, and South Korea has experimentally demonstrated for the first time that quantum technology significantly outperforms classical methods in a specific task, reducing the time required to complete the task from 20 million years to 15 minutes, truly achieving “quantum advantage.” The results were published in the journal Scientific Reports of Nature Research.
The core of the research stems from a universal challenge: how to efficiently understand a complex and noisy physical system. Traditionally, scientists need to repeatedly measure the system, inferring its behavioral characteristics, such as the device’s “noise fingerprint,” from a large amount of data. However, this process is extremely difficult for quantum systems—not only because the measurements themselves perturb the system, but also because the number of required measurements increases exponentially as the system scales, quickly becoming unfeasible.
To overcome this bottleneck, the research team from the Technical University of Denmark attempted to introduce a unique quantum resource: entangled light. Quantum entanglement is a unique phenomenon in quantum mechanics whereby two particles or light beams, once entangled, instantly reveal the state of the other, regardless of the distance between them. Leveraging this property, the team designed an experiment using entangled light pulses to probe an optical system with shared noise patterns.
The experiment employed standard optical components and telecom-band light. The team generated two entangled squeezed beams of light, one used to probe the target system and the other as a reference. The latest data demonstrate that by jointly measuring these two beams, they were able to extract significantly more effective information at once, significantly reducing measurement ambiguity.
The results were astonishing: a system characterization task that would have taken approximately 20 million years was completed in just 15 minutes using entangled light. This efficiency improvement stems not from more sophisticated equipment but from the quantum advantage of the measurement method itself. This is because the team achieved this breakthrough in a real, lossy system, rather than relying on an idealized, lossless environment.
This achievement is significant not only for its leap in speed but also for demonstrating the potential applications of quantum technology in fields such as sensing, system identification, and even machine learning.
This research opens new avenues for quantum metrology and quantum sensing, demonstrating that quantum advantage is no longer just theoretical; it is already occurring within laboratory optical systems.
Quantum advantage has moved from theoretical deduction to practical demonstration. By leveraging entanglement, we can surpass the information extraction limitations of classical physics, providing a viable engineering path for the future development of highly sensitive quantum sensors. In the fields of machine learning and big data analysis, facing the challenge of modeling massive amounts of noisy data, this efficient information extraction mechanism will also revolutionize the training process, significantly reducing energy consumption and time costs. The next step will see quantum technology move from “demonstrating capabilities” to “solving real-world problems.”
