Distant time crystals can somehow fall into the same rhythm

Physicists at TU Dortmund University showed in January 2024 that a continuous time crystal could persist inside a semiconductor, with its oscillations remaining stable for hours. Now, in a new study published in Nature Communications , Prof. Alex Greilich and his colleagues have found that multiple time crystals can emerge within the same material and synchronize their electron-nuclear spin oscillations.

Time crystals are unusual physical systems whose internal behavior repeats in a regular rhythm over time, even though they are not being driven by a repeating external signal.

In the TU Dortmund experiments, the time crystals form inside a semiconductor made from gallium arsenide with small amounts of indium and silicon. These added elements create localized electrons within the material. At temperatures close to -270 C, each electron interacts with roughly one million nearby nuclear spins.