IBM Creates First Half-Möbius Molecule and Proves Its Exotic Nature with Quantum Computing

An international team of scientists from IBM, the University of Manchester, Oxford University, ETH Zurich, EPFL and the University of Regensburg has created a molecule with a half-Mobius electronic topology. The molecule is the first to exhibit this property, in which electrons travel through its structure in a corkscrew-like pattern. The work was published in the journal Science. The molecule has the formula C13Cl2. Researchers assembled it atom by atom at IBM from a precursor synthesized at Oxford University. They removed individual atoms one at a time with voltage pulses under ultra-high vacuum at near-absolute-zero temperatures. Scanning tunneling and atomic force microscopy experiments combined with quantum computing simulations revealed an electronic structure that twists 90 degrees with each circuit. Four complete loops are required to return to the starting phase. The topology can be switched reversibly between clockwise-twisted, counterclockwise-twisted and untwisted states. An IBM quantum computer modeled the behavior of the molecule's electrons. The simulation identified helical molecular orbitals for electron attachment and showed that a helical pseudo-Jahn-Teller effect forms the unusual topology. This approach allowed the team to explore interactions that are difficult for classical computers to model exactly.