China develops record-fast quantum computers

China's latest quantum computer can handle super complex problems within a millionth of a second, 20 billion years faster than the world's fastest supercomputer.

JiuZhang quantum computer first version in Hefei. Photo: Xinhua

The JiuZhang 3 prototype breaks the record achieved by its predecessor in the series with a million-fold increase in computing speed, according to research published October 10 in the journal Physical Review Letters. The research team was led by Pan Jianwei, the lead scientist in China's national quantum research program, from the University of Science and Technology of China in Hefei, Anhui province, according to South China Morning Post .

The first Jiuzhang machine, named after an ancient math book, was built by Pan's team in 2020. This line of computers uses photons, extremely small particles moving at the speed of light, as a means of calculation maths. Each photon carries a qubit, the basic unit of quantum information. After increasing the number of photons from 76 to 113 in the first two versions of the computer, Pan and his colleagues achieved 255 in the latest version.

The team used Jiuzhang 3 to solve a complex problem based on Gaussian boson sampling, simulating the behavior of light particles moving through a maze of crystals and mirrors. The problem was initially introduced as an aimless game, although some recent research has shown that Gaussian boson sampling has some applications in cryptography. In the experiment, the researchers said Jiuzhang 3 solved the problem with the most complex sample set, demonstrating that it could handle the task within a microsecond. Frontier, the fastest supercomputer developed by the US and the most powerful computer in the world by mid-2022, would need more than 20 billion years to complete the same task.

China, the US and many other countries are participating in the race to achieve "quantum supremacy", the point at which a machine can outperform conventional computers, solving problems beyond the capabilities of machines. traditional. But they use different methods to accomplish their goals, and photon processors are just one of several types of quantum computers.

Xanadu, a Toronto company, also develops a light-based system. In a collaborative project with the National Institute of Standards and Technology (NIST) in the US, they introduced the Aurora quantum processor with 216 photons in 2022. However, despite its high speed, this machine cannot yet Replace regular computers. At the current stage, they can only operate for short periods of time in protected environments with specialized tasks and also make many mistakes.

Quantum computers are 180 million times faster than supercomputers
CHINA'S Jiuzhang quantum computer takes less than a second to handle a task that would take the world's most powerful supercomputer today nearly 5 years.

The Jiuzhang quantum computer was developed by the University of Science and Technology of China. Photo: SCMP

Chinese scientists say they have reached a new milestone in the field of quantum computing when the Jiuzhang device can perform common tasks in artificial intelligence (AI) 180 million times faster than supercomputers. The world's most powerful computer. The problems their quantum computer solves have applications for data mining, biological information, network analysis and chemical modeling research. The research team published the experimental results in Physical Review magazine, South China Morning Post reported on June 8.

"Our work comes closer to testing the practical problem with today's medium-scale quantum computers," said lead researcher Pan Jianwei, a physicist at the University of Science and Technology of China, said.

In the study, Pan's team used Jiuzhang to solve a problem that challenges conventional computing. The machine used more than 200,000 samples in the process. For the first time, researchers used quantum computers to implement and motivate two stochastic search algorithms and metallurgical simulations commonly used in the field of AI.

The world's fastest supercomputer needs 700 seconds per sample, which means it takes nearly 5 years to process the same number of samples. But Jiuzhang takes less than a second. A more extensive list of tasks gives quantum computers an advantage over conventional computers.

In traditional computers, bits are basic units of information that represent 0 or 1. Qubits go further and can represent 0, 1, or both states at the same time. This is one of the simplest examples of the peculiarities of quantum mechanics. Since the basic information of quantum computers can represent all possibilities simultaneously, in theory they are much faster and more powerful than conventional computers we use in everyday life.

However, the subatomic particles at the heart of this technology are fragile, short-lived, and prone to errors if exposed to even the slightest disturbance from their surroundings. Most quantum computers operate in extremely cold and isolated environments to avoid disruption. Jiuzhang uses light as a physical medium for calculation. Unlike other quantum computers, it does not need to operate at extremely low temperatures in a closed environment and operates stably for longer.