n388032SE Academic Article uri icon


  • 2019, The Author(s), under exclusive licence to Springer Nature Limited. According to quantum mechanics, chiral states cannot be non-degenerate eingenstates of a parity-conserving Hamiltonian. This is in contradiction to the existence of chiral moleculesa fact known as as the Hund paradox 1 . The origin of molecular and biological chirality is conjectured to be related to parity-breaking interactions 2,3 or environmental decoherence 4 , but a quantum superposition of two chiral molecular states with distinctive optical activities has never been observed 5 . To make progress in addressing these questions, it would be helpful to construct an artificial quantum system that breaks the parity symmetry and that can be prepared in a superposition of two chiral states. Here we report the synthesis of the parity-breaking antisymmetric spin exchange interaction in all-to-all connected superconducting circuits, which allows us to show various chiral spin dynamics in up to five-spin clusters. We also demonstrate the entanglement of up to five qubits in GreenbergerHorneZeilinger states based on a three-spin chiral logic gate. Our results are a step towards quantum simulation of magnetism with antisymmetric spin exhange interaction and quantum computation with chiral spin states.

published proceedings

  • Nature Physics

author list (cited authors)

  • Wang, D., Song, C., Feng, W., Cai, H., Xu, D. a., Deng, H., ... Scully, M. O.

publication date

  • January 1, 2019 11:11 AM