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Simulation of photochemical dynamics with quantum computers: post- and pre-Born-Oppenheimer approaches

Our theoretical understanding of photochemistry remains poor despite nearly a century of developments in quantum chemistry, particularly for non-radiative transitions between electronic states. After photoexcitation, a molecule may be in an energetically unstable structure on an excited electronic state. This instability can lead to ultrafast structural changes, nuclear quantum effects, and internal conversion. The dynamical and quantum mechanical nature of photochemistry hinders its simulation on conventional computers. In recent years, quantum computing has been proposed as an alternative approach to quantum chemistry. Recently, we showed how vibronic coupling Hamiltonians map onto the Hamiltonians of certain quantum devices in a controllable manner, making them an ideal analog simulation platform for vibronic photochemical dynamics. Our approach can be used to determine properties such as electronic state populations, absorption spectra, and nuclear densities. It also has the ability to incorporate environmental noise to simulate system-bath interactions. However, vibronic coupling approaches rely on fitted potential energy surfaces based on electronic structure outputs. We are now developing quantum simulation techniques with explicit treatment of electronic and nuclear interactions, with the goal of demonstrating a practical quantum advantage in the near term.

Host: Artur Izmaylov
Event series  CQIQC SeminarsQO/AMO Seminars