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

TL;DR

This paper introduces a first-principles theory for correlated many-electron dynamics interacting with a finite-temperature bath, enabling detailed simulations of open electronic systems beyond traditional approximations.

Contribution

It develops a parameter-free, ab-initio correlated-electron propagator that includes bath effects non-perturbatively, advancing the simulation of open electronic dynamics beyond the Born-Oppenheimer approximation.

Findings

Successfully simulates absorption spectra with electron-correlation effects

Models vibronic structures and decay processes in open systems

Demonstrates the theory's ability to handle non-Markovian dynamics

Abstract

In this work we develop a theory of correlated many-electron dynamics dressed by the presence of a finite-temperature harmonic bath. The theory is based on the ab-initio Hamiltonian, and thus well-defined apart from any phenomenological choice of collective basis states or electronic coupling model. The equation-of-motion includes some bath effects non-perturbatively, and can be used to simulate line- shapes beyond the Markovian approximation and open electronic dynamics which are subjects of renewed recent interest. Energy conversion and transport depend critically on the ratio of electron-electron coupling to bath-electron coupling, which is a fitted parameter if a phenomenological basis of many-electron states is used to develop an electronic equation of motion. Since the present work doesn't appeal to any such basis, it avoids this ambiguity. The new theory produces a level of detail beyond the adiabatic Born-Oppenheimer states, but with cost scaling like the Born-Oppenheimer approach. While developing this model we have also applied the time-convolutionless perturbation theory to correlated molecular excitations for the first time. Resonant response properties are given by the formalism without phenomenological parameters. Example propagations with a developmental code are given demonstrating the treatment of electron-correlation in absorption spectra, vibronic structure, and decay in an open system.