Fingernail-sized atomic clock enables ultra-precise timing systems

BEIJING, 5 May (BelTA - China Daily) - China has taken a significant step in high-precision timekeeping by mass-producing a fingernail-sized chip-scale atomic clock that is accurate to within one second over 30,000 years. The advance provides a high-precision timing foundation for strategic applications such as low-Earth-orbit satellites and underwater Beidou navigation systems.

The device, developed by Wuhan University's Satellite Navigation and Positioning Technology Research Center in Hubei province, measures just 2.3 cubic centimeters - about one-seventh the size of comparable products made in the United States - while delivering similar performance.

"Time is a strategic resource, and those who achieve the highest precision in timekeeping gain an advantage in technology, economy and even national defense," said Chen Jiehua, a professor at the center and legal representative of Zhongke Taifeisi (Wuhan) Technology Co, in an interview with Changjiang Daily.

Chen explained that precise timing is essential for navigation and positioning. "Time is distance in navigation and positioning - a time error of just one nanosecond, or one billionth of a second, leads to a positioning deviation of 0.3 meters. However, even the most accurate daily timepieces can drift by more than 10 seconds per year," he said. This challenge has driven his team to spend decades developing chip-scale atomic clocks to secure reliable, independent timing technology.

Unlike conventional clocks, atomic clocks keep time by measuring the natural vibrations of atoms, which occur at extremely stable frequencies. Traditional atomic clocks use microwave signals to interact with atoms, but the relatively long wavelength of microwaves limits how small the devices can be made.

Chip-scale atomic clocks take a different approach. They use lasers controlled by microwave signals, allowing the system to be built in a much smaller space. This design maintains high precision while significantly reducing size and power consumption.

Chen said the clocks have broad market potential. Their compact size - just a few cubic centimeters — and low power consumption of less than 200 milliwatts make them suitable for use in challenging environments such as underwater systems. In such settings, satellite signals are unavailable and solar energy cannot be relied on, so devices need their own stable, low-power time reference to stay synchronized over long periods.

Zhongke Taifeisi (Wuhan) Technology Co has achieved large-scale production of the clocks, which have already been used in time synchronization systems for underwater Beidou, low-Earth-orbit satellites and drone swarms.

Gou Fei, an official with the Yangtze River Industry Group, which holds more than 20 percent of the company's shares, said quantum technology has been identified as a priority among China's future industries. The field includes quantum precision measurement, where chip-scale atomic clocks are a core component.

"The world's smallest chip-scale atomic clock, developed by professor Chen Jiehua's team, has broken the foreign technology monopoly," Gou told Changjiang Daily. "It achieves a comprehensive leap forward with smaller size, better performance and scalable production."

The product is the first - and currently the only - chip-scale atomic clock in China to achieve commercial sales at scale. It sold several hundred units in 2024, with sales continuing to grow in 2025, Gou said.

However, large-scale production still faces challenges, particularly the high cost and performance limitations of key components such as lasers. Gou said the group plans to use its resources to help the company improve these technologies and expand automated production, reducing costs and broadening applications in both military and civilian communications.

China's 15th Five-Year Plan (2026-30) highlights the need for breakthroughs in quantum precision measurement technologies and promotes quantum technology as a new driver of economic growth.