Quantum transport through single-molecule junctions with orbital degeneracies

TL;DR

This paper develops a quantum master equation framework to analyze electron transport in single-molecule junctions with degenerate energy levels, highlighting the importance of quantum coherences absent in classical models.

Contribution

It introduces a novel master equation approach that accounts for quantum coherences in degenerate molecular states, extending beyond traditional rate-equation models.

Findings

Quantum coherences significantly affect transport properties.

New phenomena emerge due to coherent on-site dynamics.

The model applies in the weak-coupling regime.

Abstract

We consider electronic transport through a single-molecule junction where the molecule has a degenerate spectrum. Unlike previous transport models, and theories a rate-equations description is no longer possible, and the quantum coherences between degenerate states have to be taken into account. We present the derivation and application of a master equation that describes the system in the weak-coupling limit and give an in-depth discussion of the parameter regimes and the new phenomena due to coherent on-site dynamics.