China mass produces silicon-28 isotopes with over 99.99% enrichment for quantum chips

Chinese scientists achieved a major breakthrough in stable-isotope enrichment and high-purity silicon production on Monday, successfully achieving the country's first domestic mass production of silicon-28 with an isotopic abundance exceeding 99.99 percent. Key technical parameters of the product have reached internationally advanced levels, according to China National Nuclear Corporation (CNNC).

The achievement is expected to provide strong support for the independent development of core materials for silicon-based quantum computing, while also advancing frontier fields including next-generation semiconductor manufacturing, high-end navigation systems and precision metrology.

Silicon-28, a stable isotope of silicon, is widely regarded as an indispensable material for silicon-based quantum chips. Because its atomic nucleus has zero spin, it can significantly reduce environmental noise that interferes with quantum operations, earning it the nickname "the world's purest silicon."

The material was developed and produced by the Research Institute of physical and chemical engineering of nuclear industry under China Nuclear Energy Industry Corp., a subsidiary of CNNC.

The breakthrough arrives in the final year of China's Three-Year Action Plan for the High-Quality Development of Industrial Applications of Nuclear Technology (2024-26). It marks a major stride toward establishing an independent, secure and efficient stable-isotope industry chain and is expected to propel China's nuclear technology application sector from isolated technological advances to more integrated industrial growth.

According to Yu Dapeng, an academician of the Chinese Academy of Sciences, the achievement addressed a critical bottleneck in silicon-based quantum computing by ensuring access to a key material that has long been in short supply. It will help pave the way for large-scale qubit control in future silicon-based quantum computing systems.

Lei Zengguang, an academician of the Chinese Academy of Engineering, hailed the mass production of high-abundance silicon-28 as a milestone achievement born from years of committed research and technological development. Looking beyond silicon-28, Lei said researchers will press forward with the development of a range of stable-isotope products to meet major national needs in such fields as nuclear energy, nuclear medicine, aerospace, quantum information, particle physics and deep-space exploration.

Stable isotopes serve as critical foundational materials for frontier technologies and national security. They also play irreplaceable roles in nuclear medical imaging, precision radiotherapy, nuclear forensics, environmental tracing and fundamental physics research. For decades, stable-isotope production technologies have remained highly concentrated globally and protected by significant technical barriers, making them a key factor affecting supply-chain security in sectors such as quantum technology, advanced semiconductors and high-end medical equipment.

With the guidance and support of the China Atomic Energy Authority, CNNC has enhanced the country's stable-isotope capabilities by orchestrating innovation throughout the nuclear technology industrial chain. The effort has led to the establishment of a number of isotope production bases, including those centered on the Research Institute of physical and chemical engineering of nuclear industry, the Qinshan Nuclear Power Base, the Nuclear Power Institute of China, the China Institute of Atomic Energy and other research and production facilities.

In particular, project teams at the research institute of physical and chemical engineering of nuclear industry have continued advancing the engineering and industrial application of stable-isotope technologies, overcoming a series of world-class technical challenges in isotope separation, purification and conversion.

The institute has successfully produce 26 stable isotopes across 12 elements, including molybdenum, tellurium, nickel, zinc, silicon and ytterbium. These achievements are contributing to the establishment of a complete innovation chain that connects fundamental research to industrial application, while bolstering the development of China's strategic emerging industries through greater technological self-reliance.

Global Times