Superconducting transport through a vibrating molecule

TL;DR

This paper investigates how superconducting transport through a vibrating molecule is affected by phonon interactions, revealing complex MAR structures and parity effects using advanced theoretical formalisms.

Contribution

It introduces a detailed analysis of inelastic MAR processes in superconducting molecular junctions, connecting Keldysh and Landauer formalisms for the first time.

Findings

Rich subgap structures due to phonon emission

Even-odd parity effects in MAR channels

Connection established between Keldysh and Landauer approaches

Abstract

Nonequilibrium electronic transport through a molecular level weakly coupled to a single coherent phonon/vibration mode has been studied for superconducting leads. The Keldysh Green function formalism is used to compute the current for the entire bias voltage range. In the subgap regime, Multiple Andreev Reflection (MAR) processes accompanied by phonon emission cause rich structure near the onset of MAR channels, including an even-odd parity effect that can be interpreted in terms of an inelastic MAR ladder picture. Thereby we establish a connection between the Keldysh formalism and the Landauer scattering approach for inelastic MAR.