Distant time crystals inside a semiconductor synchronize oscillations, surprising physicists
Physicists at TU Dortmund University discovered that multiple time crystals formed in a semiconductor can synchronize their electron-nuclear spin oscillations across distances up to 40 micrometers. The coupling is mediated by spin-polarized electrons, allowing the exotic systems to lock to a common frequency. The finding, published in Nature Communications, could aid future spin-based devices.
The experiments rely on a gallium arsenide semiconductor doped with indium and silicon, which traps localized electrons. At temperatures near -270°C, each electron interacts with roughly one million surrounding nuclear spins. A pump laser aligns electron spins, which transfer polarization to the nuclei; a weak magnetic field then induces rotation, and feedback between the two spin systems sustains the oscillations indefinitely.
The synchronization mechanism differs fundamentally from Huygens' 1665 pendulum clock observation. Rather than mechanical coupling through a shared support, the time crystals communicate via spin-polarized electrons moving through the material. When illuminated by a broad laser beam, regions that would otherwise oscillate at slightly different frequencies lock together—but only within a 40-micrometer range, beyond which independent oscillation resumes.
This discovery could influence the development of spin-based electronics, where information is encoded in electron spin rather than charge. Synchronized spin oscillators might enable new approaches to signal processing, timing devices, or quantum information systems. However, the extreme low-temperature requirements and the complexity of semiconductor fabrication mean practical applications remain distant. The finding may also deepen theoretical understanding of non-local coupling in many-body systems, potentially informing future research in quantum physics and materials science.