Vibrationally coupled electron transport in single-molecule junctions: The importance of electron-hole pair creation processes

TL;DR

This paper reviews how electron-hole pair creation processes are essential for understanding vibrational effects in electron transport through single-molecule junctions, revealing their role in phenomena like negative differential resistance and rectification.

Contribution

It highlights the significance of electron-hole pair creation processes in vibrationally coupled electron transport, a focus that was previously underappreciated.

Findings

Electron-hole pair creation processes are key to vibrational excitation.

These processes influence phenomena like negative differential resistance.

Temperature significantly affects electron transport via these processes.

Abstract

Vibrationally coupled electron transport through single-molecule junctions is considered. Reviewing our recent theoretical work, we show that electron-hole pair creation processes represent the key to understand the vibrational excitation characteristic of a single-molecule contact. Moreover, these processes can lead to a number of interesting transport phenomena such as, for example, negative differential resistance, rectification, mode-selective vibrational excitation and a pronounced temperature dependence of the electrical current. Thus, electron-hole pair creation processes are crucial to elucidate the basic mechanisms of vibrationally coupled electron transport through a single-molecule contact, despite the fact that these processes do not directly contribute to the electrical current that is flowing through the junction.