China and Austria develop first nuclear clocks; China's more stable, Nature says

China and Austria develop first nuclear clocks; China’s more stable, Nature says

October 7, 2026 Rachel Kim – Technology Editor Technology

Scientific teams working independently in Vienna and Beijing have developed the world’s first two operating nuclear clocks, with initial results indicating that the timekeeper built in China is about six times as stable as the device in Austria, according to papers published this week in the journal Nature.

    The Tech TL;DR:

  • Two independent research teams in Beijing and Vienna built the world’s first operating nuclear clocks using thorium-229 nuclei trapped in calcium fluoride crystals.
  • Data published in Nature shows the Beijing clock is approximately six times as stable as the Vienna clock.
  • Physicists envision future applications in satellite navigation, high-speed data synchronization, metrology, and fundamental physics research like dark matter detection.

Independent Development in Beijing and Vienna

The two devices represent the next generation of atomic clocks, which are ultra-accurate timekeeping machines first created in 1949. Traditional atomic clocks measure time by using lasers or microwaves to make electrons jump back and forth between two energy levels in an atom’s shell, utilizing elements such as cesium or strontium. In contrast, the new nuclear clocks measure time by using lasers to make subatomic particles—protons and neutrons—jump between energy levels inside the atomic nucleus itself. Because an atomic nucleus is much smaller than the electron shell surrounding it, tracking these inner transitions can potentially attain even higher levels of accuracy.

The projects were developed independently by separate teams. In China, the research was led by Tsinghua University, including physicist Shiqian Ding, while the Austrian team at TU Wien was led by physicist Thorsten Schumm, who has been working toward this goal since 2008. Thorsten Schumm noted that "now we have a fierce but friendly global competition." Shiqian Ding stated that the creation of a nuclear clock was something physicists dreamt of for almost 50 years, adding that the dual achievement shows the concept works and is not dependent on one particular technical implementation.

A calcium fluoride crystal, in its holder, that incorporates large numbers of thorium nuclei is seen inside the vacuum
Photo: Reuters

Beijing Timepiece Outperforms Vienna Instrument in Stability

According to the Nature publications, the Beijing team’s timepiece achieved roughly six times the stability of the Vienna instrument. Furthermore, the Beijing scientists demonstrated that two separately grown crystals maintained identical timekeeping, signaling that these advanced devices can be reliably reproduced. Meanwhile, the Vienna team utilized its clock to search for dark matter. While that particular experiment did not detect dark matter, the nuclear clock performed at the level of the best conventional atomic clocks.

The two groups utilized different experimental approaches while relying on the same core isotope, thorium-229, trapped in solid-state calcium fluoride crystals. Thorsten Schumm explained that the Vienna clock features slightly better thorium crystals with higher optical properties and concentration, whereas the Beijing team deployed a stronger laser. “So already by putting these components together, we can build a significantly better clock,” Schumm observed.

The World's First Nuclear Clocks Are Ticking, Opening a New Way to Investigate Dark Matter and Ot…

Nuclear Clocks Could Improve Navigation and Physics Research

Despite the breakthrough, researchers emphasize that the technology remains far from its ultimate target performance. Thorsten Schumm outlined potential future applications for nuclear clocks across several infrastructure-critical domains, including satellite-based navigation, the precise synchronization of data transfer, surveying, and metrology.

Beyond commercial synchronization, physicists view the devices as a new instrument to investigate fundamental physics. “It gives access to a whole new physics universe,” Schumm told Reuters.

China and Austria develop first nuclear clocks; China's more stable, Nature says
Photo: Business Recorder
# Conceptual thorium-229 nuclear excitation workflow
# Laser interrogation of solid-state calcium fluoride (CaF2) crystal lattice
import numpy as np

def calculate_nuclear_transition_stability(laser_power_mw, crystal_purity_pct):
    base_stability_factor = 6.0 # Observed relative scale factor in Nature data
    optimized_metric = (laser_power_mw * 0.5) + (crystal_purity_pct * 1.5)
    return optimized_metric * base_stability_factor

print("Nuclear clock state initialized:", calculate_nuclear_transition_stability(120, 99.9))

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