Quantum chemistry simulation of ground- and excited-state properties of the sulfonium cation on a superconducting quantum processor

The computational description of correlated electronic structure, and particularly of excited states of many-electron systems, is an anticipated application for quantum devices. An important ramification is to determine the dominant molecular fragmentation pathways in photo-dissociation experiments of light-sensitive compounds, like sulfonium-based photo-acid generators used in photolithography. Here [1] we simulate the static and dynamical electronic structure of the sulfonium cation, taken as a minimal model of a triply bonded sulfur cation, on a superconducting quantum processor of the IBM Falcon architecture.

To this end, we combine a qubit reduction technique with variational and diagonalization quantum algorithms and use a sequence of error-mitigation techniques. We compute dipole structure factors and partial atomic charges along ground- and excited-state potential energy curves, revealing the occurrence of homo- and heterolytic fragmentation.

[1] M. Motta et al, https://arxiv.org/abs/2208.02414 (2022)