Physicists have discovered a surprisingly simple way to reproduce one of the most fascinating models in modern physics—linked to black holes, quantum chaos and exotic electronic materials—using ultracold atoms trapped in light.

Heavy polar molecules are some of the most sensitive tools physicists have for probing what lies beyond the Standard Model, the theory that describes the particles and forces we know about. But turning that sensitivity into precise, trustworthy measurements has long been held back by one stubborn problem: Stray electric and magnetic fields drown out the tiny signals researchers are actually looking for.

In most everyday materials, such as copper, silver and silicon, the behavior of electrons is relatively predictable. In quantum materials, however, electrons can interact in complex ways, giving rise to collective electronic states with remarkable properties. Understanding how these states emerge—and, ultimately, how to control them—is one of the central challenges in quantum materials research.

Reliably generating controlled miniature rotations has long been a challenge: Chemical propulsion systems wear out, and methods that use electric or magnetic fields require complex setups. A team from KIT’s Institute of Microstructure Technology (IMT) and the Suzhou Institute of Nano-tech and Nano-bionics (SINANO) at the Chinese Academy of Sciences has now demonstrated that flow at a water surface alone is sufficient to rotate a floating object in a fixed direction. Their research is published in the journal Science Advances.