Quantum computing used to build impossible half-Möbius topology molecule with implications for materials and drug discovery

A paper published in the journal Science describes the creation of a new molecule with half-Mobius topology. Researchers from IBM, the University of Manchester, Oxford University, ETH Zurich, EPFL and the University of Regensburg synthesized and characterized the compound C13CL2. The molecule consists of 13 carbon atoms and two chlorine atoms. Its electronic structure follows a helical path in which an electron experiences a 90-degree phase shift after one revolution around the ring and requires four full loops to return to the original phase and orientation. The team used IBM superconducting-qubit quantum processors to characterize the molecule. Runs of up to 100 qubits on the IBM Heron processor, accessed through the IBM Quantum Platform and the IBM Pittsburgh system, supported the work along with the SqDRIFT algorithm to determine the lowest-energy state in an active space of 2 to the 100th power. The molecule can switch between right-handed half-Mobius, left-handed half-Mobius or topologically trivial configurations. This property could enable its use as a building block for quantum sensing devices, chiral sensors and spin filters. Quantum simulation identified a helical pseudo-Jahn-Teller effect as the cause of the twisted topology. The work also confirmed predictions of twisted molecular orbitals for electron attachment. The molecule was produced using precise voltage pulses in ultra-high vacuum at near-absolute-zero temperatures.