Simulating cavity-modified ultrafast charge migration in molecules with time-dependent configuration interaction methods

In recent years, polaritonic chemistry has gained significant attention for its potential to alter chemical reactivity through the strong coupling of molecules with cavity modes. Alongside experimental advances in cavity-modified photochemistry, new theoretical methods have emerged for explaining and predicting polaritonic phenomena. Among these, the quantum electrodynamics time-dependent configuration interaction (QED-TDCI) method simulates the real-time laser-induced dynamics of molecules within cavities. The coupling of the molecule to the cavity is included using the Pauli-Fierz Hamiltonian, which is formed in the direct product basis of electronic CI states and photon number states. The resulting mixed electron-photon wavefunction is propagated in the presence of a time-dependent external electric field using TDCI techniques. The QED-TDCI method is demonstrated to modify the ultrafast charge migration and dipole-switching dynamics of molecules in cavities.