학술논문

Beyond Marcus theory and the Landauer-Buttiker approach in molecular junctions. II. A self-consistent Born approach
Document Type
Working Paper
Source
The Journal of Chemical Physics 152 (6), 064103 (2020)
Subject
Physics - Chemical Physics
Condensed Matter - Mesoscale and Nanoscale Physics
Language
Abstract
Marcus and Landauer-Buttiker approaches to charge transport through molecular junctions describe two contrasting mechanisms of electronic conduction. In previous work, we have shown how these charge transport theories can be unified in the single-level case by incorporating lifetime broadening into the second-order quantum master equation. Here, we extend our previous treatment by incorporating lifetime broadening in the spirit of the self-consistent Born approximation. By comparing both theories to numerically converged hierarchical-equations-of-motion (HEOM) results, we demonstrate that our novel self-consistent approach rectifies shortcomings of our earlier framework which are present especially in the case of relatively strong electron-vibrational coupling. We also discuss circumstances under which the theory developed here simplifies to the generalised theory developed in our earlier work. Finally, by considering the high-temperature limit of our new self-consistent treatment, we show how lifetime broadening can also be self-consistently incorporated into Marcus theory. Overall, we demonstrate that the self-consistent approach constitutes a more accurate description of molecular conduction while retaining most of the conceptual simplicity of our earlier framework.
Comment: Version accepted in J. Chem. Phys