Chinese scientists developed a quantum dot device that emits photon pairs with 98.3 percent purity and 29.9 percent generation efficiency under pulsed excitation. The research, published in Nature Materials, sets a new benchmark in quantum optics for reliable two-photon sources.
The result advances the global pursuit of photonic technologies for encryption, medical imaging, and precision sensing. Two-photon sources enable higher spatial resolution and can serve as a foundation for theoretically unbreakable quantum networks.
The device was developed by a team at the Beijing Academy of Quantum Information Sciences in collaboration with the Chinese Academy of Sciences’ Institute of Semiconductors. The research was led by chief scientist Yuan Zhiliang.
Yuan described the results as “international best-in-class.” The achievement addresses the difficulty of coaxing quantum dots to emit exactly two photons simultaneously, a challenge described as “like trying to balance two marbles on a needle” by the South China Morning Post.
Ding Fei, a physicist at Leibniz University in Germany, wrote in a research briefing that he was “truly impressed by the result.” The breakthrough adds to a series of recent quantum achievements from Chinese laboratories.
In July 2025, a team at Sun Yat-sen University published work in Nature demonstrating a nano-scale entangled photon-pair source with 99.4 percent fidelity. Earlier, in February 2025, researchers at the University of Science and Technology of China reported a single-photon source reaching 71.2 percent efficiency.
The Beijing Academy of Quantum Information Sciences collaborates with the Chinese Academy of Sciences’ Institute of Semiconductors on advanced quantum research. The institute focuses on semiconductor physics and device fabrication to support national quantum initiatives.
