China has made a breakthrough in quantum computing. Scientists there have created a quantum computer that solved a complex problem in only four minutes, a problem that would take even the fastest classical supercomputer over 2.6 billion years to complete. This achievement is a sign that quantum computing is no longer just science fiction, but a powerful reality with huge potential.
The Chinese team used a 76-qubit quantum computer prototype named Jiuzhang. Unlike regular computers that use electrical signals, Jiuzhang works using light. It uses lasers, mirrors, prisms, and photon detectors to run its calculations.
This method, called Gaussian Boson Sampling, measures how particles of light—known as photons—move through an optical network. Jiuzhang was able to detect 76 photons at the same time. This is a world record. Classical computers cannot even reach this level with five photons.
This kind of result is not just a fancy lab experiment. It opens the door to many real-world uses. Quantum computers like Jiuzhang could be used in quantum chemistry, advanced mathematics, and even to help build a quantum internet in the future.
Traditional computers use bits to represent either a 0 or 1, quantum computers use qubits. Qubits can be 0, 1, or both at the same time. This is thanks to two key principles of quantum physics, superposition and entanglement.
These properties allow quantum machines to test many possible answers at once. In simple words, quantum computers can solve some problems way faster than any computer we’ve ever had.
In this experiment, Jiuzhang completed a task known as boson sampling. It’s a very hard problem for classical computers. It involved 50 photons, 100 input channels, 100 output channels, 300 beam splitters, and 75 mirrors.
The photons were bounced around and split many times before the system gave the final result. Jiuzhang found this solution in just 200 seconds. In comparison, a supercomputer like Sunway TaihuLight—one of the fastest in the world—would have needed billions of years to solve the same problem.
This new result is called quantum supremacy. That’s the moment when a quantum computer does something that a classical computer simply cannot do in any reasonable time. Google made a similar claim in 2019 when its quantum computer Sycamore solved a problem in 200 seconds that would have taken the world’s most powerful supercomputer 10,000 years.
But China has pushed those limits even further. Jiuzhang’s four-minute calculation is not only faster but solves a more complex problem. So, how does this quantum computer work? Jiuzhang is an optical quantum computer, which means it uses light particles to compute.
Lasers send photons through an optical chip that’s full of tiny mirrors and beam splitters. Each time a photon hits a beam splitter, it can take multiple paths at the same time—something only possible in quantum physics.
This setup allows photons to act like tiny travelers going through a maze. Their movements follow the laws of quantum mechanics, and by watching where they end up, researchers can find answers to problems that would take traditional computers an impossible amount of time.
What’s more amazing is that Jiuzhang worked without using any shortcuts that classical computers might rely on. Researchers tested the system using regular light, and the results were completely different. They also checked for special patterns that only happen when photons interfere in a quantum way. All the data confirmed that this was a true quantum result.
Even though this achievement is incredible, it doesn’t mean regular computers will disappear. Classical computers are still great for many everyday tasks. Quantum machines like Jiuzhang are best for very specific, highly complex problems that are too much for today’s tech.
Quantum computers are still in their early stages. They are fragile, expensive, and hard to maintain. But every step forward, like this one by the Scientists, shows that we are getting closer to a time when quantum computers will become part of our everyday technology.
The details of the Jiuzhang experiment have been published in the journal Science.
