An international team of scientists from IBM, The University of Manchester, Oxford University, ETH Zurich, EPFL and the University of Regensburg have synthesized a molecule with a unique topology that has never been observed in nature. Its structure is so unusual that it requires four full rotations to return to its starting point – even more complex than the famous Möbius strip, which requires only two.

The molecule itself is surprisingly simple in composition: 13 carbon atoms and two chlorine atoms linked together in a ring. Yet its three-dimensional configuration is extremely unusual.

The researchers explain that if a hypothetical particle were to travel along the path of this molecule, it would have to circle the loop four times before returning to the same side of the structure.

This makes it the first known molecule with a topology requiring four turns. By comparison, a classic Möbius strip has only a single half-twist, meaning a traveler must go around the surface twice to reach the same orientation.

The molecule was assembled on a thin gold surface at extremely low temperatures. The scientists manipulated atoms one at a time using an atomic force microscope (AFM) and a scanning tunneling microscope (STM). In effect, the researchers constructed the molecule manually at the atomic level.

Its unusual twisted geometry arises from the behavior of electron waves. Electrons spread across the entire molecular structure and form complex interference patterns. These interactions force the ring into its unusual topology.

The molecule was assembled atom-by-atom on a gold surface using atomic microscopes. Researchers can switch its structure between left-twisted, right-twisted, and flat states using electromagnetic pulses. Calculations were verified using an IBM quantum computer. The discovery opens new possibilities for topological molecules in nanotechnology and sensing.

Source: Science

Image: University of Manchester