Chinese Scientists Develop a Nanoscale Two-Photon Device with Record Entangled Photon Pair Generation Efficiency in the Context of Quantum Optics. This technology, commonly referred to as a “nano two-photon factory”, significantly increases the generation rates of twin photons and could lead to breakthroughs in quantum computing, secure communication, and high-precision sensing.
Breakthrough Overview
A device consisting of a nano-sized solid-state “artificial atom” structure coupled with an ultrahigh-quality optical microcavity was developed by the team at Sun Yat-sen University in Guangzhou. This study leading by Professors Wang Xuehua and Liu Jin published in Nature realizes spontaneous two-photon emissions with the intensity arrives single-photon level, they presented an on-demand entangled photon-pair source with 99.4% fidelity. This “psychic link” between photons improves precision in quantum metrology and is a foundation of photonic quantum chips.
The device opens a dedicated path to twin photon generation, bringing efficiency from less than 0.1% to ~50% in experiments. Reviewers called it a “groundbreaking advance” in two-photon research.
Technical Innovation
When they do, traditional quantum dots have trouble emitting exactly two photons, reliably — almost like trying to balance marbles on the tip of a needle. The team thus developed a cavity-induced scheme for the precise control of emission at the micro-nano scale, supporting triggered generation of entangled pairs on demand. Advances in semiconductor processing made theoretical predictions from the 1960s imaginable.
Key Performance Metrics
| Metric | Achievement | Improvement Over Prior |
| Two-Photon Fidelity | 99.4% | Record-high |
| Radiation Efficiency | ~50% | From <0.1% |
| Paired Emission Rate | 98.3% (pulsed excitation) | Best-in-class |
| Generation Efficiency | 29.9% | International lead |
These metrics make scalable quantum networks viable.
Potential Applications
The technology promises clearer medical images by doubling the spatial resolution in precise measurements. It strengthens quantum encryption that can’t be broken, quantum computing that works, and sensors that work better. Applications range from next-generation metrology to quantum communication security.
Global Recognition
Nature reviewers said that the faithfulness of the entangled pairs was the best they had ever seen. A different team from the Academy of Quantum Information Sciences in Beijing, led by Yuan Zhiliang, found similar results in Nature Materials, with 98.3% of paired photons under pulsed conditions. Ding Fei, a German physicist, said it was “truly impressive.” As of early 2026, this puts China at the top of the field of quantum photonics.