Separate time crystals inside a semiconductor can “find” each other across surprising distances and lock into the same rhythm.
Researchers at TU Dortmund University demonstrated the effect using a semiconductor system in which electron and nuclear spins form continuous time crystals. Their latest experiments, published in Nature Communications, reveal that spatially separated oscillators can lock to the same frequency even when they begin with different rhythms.
The finding builds on the team’s earlier demonstration of an unusually robust continuous time crystal in a semiconductor. That system produced persistent electron-nuclear spin oscillations with coherence lasting for hours, giving the researchers a stable platform for exploring what happens when several time crystals occupy the same material.
How Continuous Time Crystals Keep Their Rhythm
Unlike an ordinary crystal, whose atoms repeat in space, a time crystal is defined by behavior that repeats in time. In this experiment, the rhythm is not imposed by a periodically pulsing source. The semiconductor is continuously illuminated, while the coupled spin system develops its own oscillation frequency. The system is not oscillating without an energy source. Instead, continuous optical pumping maintains the nonequilibrium state while the repeating dynamics emerge from interactions inside the material.
The material contains gallium arsenide with small amounts of indium and silicon, which help localize electrons. It is cooled to around −270°C (−454°F), only a few degrees above absolute zero. Each localized electron interacts with roughly one million surrounding nuclear spins.
A laser prepares the electron spins in a preferred orientation. Their polarization is then transferred to the nuclei. When a weak magnetic field is applied, the nuclear-spin polarization begins rotating, and feedback between the electron and nuclear spins produces sustained oscillations. A second laser allows the researchers to track that motion.
When Separate Time Crystals Synchronize
Different parts of the semiconductor are not perfectly identical at the microscopic level, so isolated regions naturally develop slightly different oscillation frequencies. The striking behavior appears when several regions are excited at once. Instead of continuing at their individual rates, nearby time crystals can adjust until they share a common frequency.
Synchronization is widespread in physics and biology, but the classic comparison dates to 1665, when Christiaan Huygens noticed that two pendulum clocks mounted on the same support eventually fell into step. Their weak mechanical interaction was enough to coordinate their motion.
Time Crystals Connect Across Surprising Distances
Nothing physically connects the semiconductor oscillators in the same way. Instead, the experiments point to spin-polarized electrons moving through the material as the messenger between them.
The observed synchronization extends to separations of about 40 micrometers (0.0016 inches), a distance that closely matches the characteristic electron spin diffusion length in the semiconductor. Beyond that range, the oscillators stop locking together and continue at their own frequencies. Forty micrometers may sound tiny, but it is more than one thousand times the characteristic size of an individual oscillator. At the scale of the underlying spin system, that makes the interaction remarkably long-range.
Rather than treating each oscillating region as an isolated time crystal, a synchronized collection can behave as a larger time crystal built from many interacting units. That introduces the possibility of studying collective behavior, information transfer, and complex dynamics in networks of spin oscillators within a solid-state device.
Reference: “Non-local synchronization of continuous time crystals in a semiconductor” by Alex Greilich, Nataliia E. Kopteva, Vladimir L. Korenev, Philipp A. Haude, Linus Kunze, Ben W. Grobecker, Sergiu Anghel, Markus Betz and Manfred Bayer, 22 July 2026, Nature Communications.
DOI: 10.1038/s41467-026-75714-1
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