Decoherence and Energy Relaxation in the Quantum-Classical Dynamics for Charge Transport in Organic Semiconducting Crystals: an Instantaneous Decoherence Correction Approach

TL;DR

This paper introduces an instantaneous decoherence correction (IDC) method for modeling decoherence and energy relaxation in charge transport within organic semiconducting crystals, improving understanding of environmental effects on carrier dynamics.

Contribution

The paper develops a novel IDC approach incorporating detailed balance with energy-dependent reweighing, enhancing quantum-classical simulations of charge transport in organic semiconductors.

Findings

IDC enhances diffusion in charge transport models.

Energy relaxation weakens the diffusion enhancement caused by IDC.

Different reweighing factors lead to distinct relaxation regimes and temperature dependencies.

Abstract

We explore an instantaneous decoherence correction (IDC) approach for the decoherence and energy relaxation in the quantum-classical dynamics of charge transport in organic semiconducting crystals. These effects, originating from environmental fluctuations, are essential ingredients of the carrier dynamics. The IDC is carried out by measurement-like operations in the adiabatic representation. While decoherence is inherent in the IDC, energy relaxation is taken into account by considering the detailed balance through the introduction of energy-dependent reweighing factors, which could be either Boltzmann (IDC-BM) or Miller-Abrahams (IDC-MA) type. For a non-diagonal electron-phonon coupling model, it is shown that the IDC tends to enhance diffusion while energy relaxation weakens this enhancement. As expected, both the IDC-BM and IDC-MA achieve a near-equilibrium distribution at finite temperatures in the diffusion process, while the Ehrenfest dynamics renders system tending to infinite temperature limit. The resulting energy relaxation times with the two kinds of factors lie in different regimes and exhibit different dependence on temperature, decoherence time and electron-phonon coupling strength, due to different dominant relaxation process.