Non-adiabatic and time-resolved photoelectron spectroscopy for molecular systems

Abstract

We quantify the non-adiabatic contributions to the vibronic sidebands of equilibrium and explicitly time-resolved non-equilibrium photoelectron spectra for a vibronic model system of Trans-Polyacetylene. Using exact diagonalization, we directly evaluate the sum-over-states expressions for the linear-response photocurrent. We show that spurious peaks appear in the Born-Oppenheimer approximation for the vibronic spectral function, which are not present in the exact spectral function of the system. The effect can be traced back to the factorized nature of the Born-Oppenheimer initial and final photoemission states and also persists when either only initial, or final states are replaced by correlated vibronic states. Only when correlated initial and final vibronic states are taken into account, the spurious spectral weights of the Born-Oppenheimer approximation are suppressed. In the non-equilibrium case, we illustrate for an initial Franck-Condon excitation and an explicit pump-pulse excitation how the vibronic wavepacket motion of the system can be traced in the time-resolved photoelectron spectra as function of the pump-probe delay.

References in corpus (6)

• Simulating pump-probe photo-electron and absorption spectroscopy on the attosecond time-scale with time-dependent density-functional theory
• Ab-initio angle and energy resolved photoelectron spectroscopy with time-dependent density-functional theory
• A novel general mapping for bosonic and fermionic operators in Fock space
• Exact-diagonalization study of exciton condensation in electron bilayers
• Long-lived oscillatory incoherent electron dynamics in molecules: trans-polyacetylene oligomers
• Reduced purities as measures of decoherence in many-electron systems

Cited by in corpus (6)

• Atoms and Molecules in Cavities: From Weak to Strong Coupling in QED Chemistry
• Cavity Born-Oppenheimer Approximation for Correlated Electron-Nuclear-Photon Systems
• Kohn-Sham Approach to Quantum Electrodynamical Density Functional Theory: Exact Time-Dependent Effective Potentials in Real Space
• Optimized Effective Potential for Quantum Electrodynamical Time-Dependent Density Functional Theory
• Ab-initio Optimized Effective Potentials for Real Molecules in Optical Cavities: Photon Contributions to the Molecular Ground state
• Exact functionals for correlated electron-photon systems