On Thursday, one of China's top quantum research groups published a scientific report in Nature and made a similar statement: they have already achieved quantum supremacy. Their Jiuzhang computer system only took a few minutes to solve the problem that the world's third most powerful supercomputer would take 2 billion years to complete. If you put this problem on Earth's most powerful supercomputer, it would also take 600 million years to successfully solve the difficult challenge.
Two systems from two technology giants have different ways of operating. Google creates quantum circuits with superconducting and superconducting metals, while the team at the Chinese University of Science and Technology achieves quantum superiority with photons.
There is still no quantum computer modern enough to do a useful job in practice. But the new Chinese achievement shows that in two fundamentally different ways, science can still create technology that surpasses supercomputers. The quantum computer industry is still in its infancy eager to receive the good news. Mr. Lu Chaoyang, a professor of physics from the University of Science and Technology and also one of the researchers who contributed to the breakthrough, called this the "necessary step" to create the "quantum computer. large-scale death no longer has major errors ”.
In recent years, Google and other names in the quantum computer industry, such as IBM, Microsoft, Amazon, Intel and many other big startups, have spent tons of money on developing quantum computer hardware.
Quantum computing power comes mainly from qubits. Like bits in conventional computers with the ability to represent two values of 0 or 1, qubits can take advantage of quantum mechanics to exist in a superposition state, i.e. capable of being either 0 or 1. With enough qubits and letting them work together in harmony, the computational power of quantum computers can surpass even the most powerful supercomputers.
But that is still the potential. Quantum computer experts have not had a way to combine sufficient quantities of qubits to have an efficient computational system. Google and the team from China can claim quantum dominance because they can bundle a sizable amount of qubits into a system.
The focus of Google's testing is a superconducting chip called Sycamore with 54 qubit power, placed in a cold environment close to absolute zero. One qubit does not "make up", but the help from the remaining 53 qubit has helped the system solve a carefully selected example problem. We don't know how many qubits a quantum computer will need to be efficient in real life, experts predict the number will be anywhere from a few hundred to several million.
The Chinese team also used a statistical test to test the system's capabilities, but the Jiuzhang machine's way of transporting quantum data is based on photons traveling inside the optical fiber. Measuring each photon after the journey has finished over the cable is similar to the Google chip reading the value of a qubit; Both of these processes produce results.
The team of experts wrote code to bring the new math problem solved by quantum computer to Thái Hồ Quang, the most powerful supercomputer in China and the third fastest system in the world, but the power of quantum computers is too outstanding. According to calculations, Thai Ho Quang will need 2 billion years to calculate the results that Jiuzhang completed in more than 3 minutes.
Thanks to the support from the Chinese government, the team led by Pan Jianwei has achieved great success. Their past successes also include the ability to encode the furthest distance ever recorded, using satellites specialized in quantum communications to conduct a video call between China and Austria. . In theory, quantum encryption is absolutely safe.
Another big difference for Jiuzhang compared to Sycamore: it is not easy to reprogram a system that uses photons for other calculations. However, Christian Weedrook, CEO and founder of startup Xanadu, another photon computer research enterprise, said the achievement is still remarkable, and there are other ways to overcome the obstacles. Technology limits set out.
"This is a milestone in photon quantum computing, and it benefits all of us," said CEO Weedbrook.
Professor Lu Chaoyang said that he and his colleagues are working on assembling a more advanced and easier to edit version of Jiuzhang. Many other researchers have demonstrated that the Chinese expert group's quantum predominance testing process can be applied to the study of molecular properties, or to solve mathematical diagrams related to intersection. information and social networks.
Chinese scientists have shown that there exists more than one way to gain quantum supremacy, but the act of solving the problem to prove the invisible power opens up more questions than answers. What other ways are there to create quantum advantage? Will quantum computers reach their limit soon? What future will be when quantum computers become universal?
Time will answer a series of difficult questions.