A correlated-polaron electronic propagator: Open electronic dynamics beyond the Born-Oppenheimer approximation

• Published in: The Journal of chemical physics Vol. 137; no. 22; p. 22A547
• Main Authors: Parkhill, John A., Markovich, Thomas, Tempel, David G., Aspuru-Guzik, Alan
• Format: Journal Article
• Language: English
• Published: United States 14.12.2012
• ISSN: 0021-9606; 1089-7690; 1089-7690
• DOI: 10.1063/1.4762441

In this work, we develop an approach to treat correlated many-electron dynamics, dressed by the presence of a finite-temperature harmonic bath. Our theory combines a small polaron transformation with the second-order time-convolutionless master equation and includes both electronic and system-bath correlations on equal footing. Our theory is based on the ab initio Hamiltonian, and is thus well-defined apart from any phenomenological choice of basis states or electronic system-bath coupling model. The equation-of-motion for the density matrix we derive includes non-Markovian and non-perturbative bath effects and can be used to simulate environmentally broadened electronic spectra and dissipative dynamics, which are subjects of recent interest. The theory also goes beyond the adiabatic Born-Oppenheimer approximation, but with computational cost scaling such as the Born-Oppenheimer approach. Example propagations with a developmental code are performed, demonstrating the treatment of electron-correlation in absorption spectra, vibronic structure, and decay in an open system. An untransformed version of the theory is also presented to treat more general baths and larger systems.