China builds fastest quantum computer Speed of Jiuzhang 4.0 prototype is a result of use and control of photons A team of Chinese scientists has developed the world's fastest quantum computer prototype, named Jiuzhang 4.0, capable of solving complex mathematical problems in less than the blink of an eye — tasks that even for the world's most powerful supercomputer would take longer than the age of the entire universe to crack. The findings, published in the journal Nature on Wednesday, push the quantum advantage in computing to an unprecedented level, demonstrating China's leading position in the field. A quantum computer operates on the laws of quantum mechanics. Its basic building blocks, called quantum bits or qubits, can exist in a superposition of both 0 and 1 simultaneously — unlike conventional bits, which are either 0 or 1. This allows quantum computers to explore many computational paths in parallel, providing exponential speedup for certain tasks, such as solving some mathematical problems and simulating quantum systems. Current mainstream quantum computing technological routes include superconducting, ion trap, photonic, and neutral atom systems. The Jiuzhang series, photonic quantum computers, encodes information in particles of light, and its speed depends on the ability to manipulate and control these photons. However, in the development of large-scale photonic quantum processors, inevitable photon loss — a major source of computational error — has long been a serious constraint. As the optical network grows larger and more complex, photons can easily get "lost" in the maze, significantly degrading computational power. To address the problem, the research team, led by the University of Science and Technology of China, developed a high-efficiency optical parametric oscillator light source and a spatiotemporally hybrid-coded interferometer, laying the groundwork for building a fault-tolerant photonic quantum processor. They integrated 1,024 high-efficiency squeezed-state optical fields into a