Electronic Transport through Magnetic Molecules with Soft Vibrating Modes

TL;DR

This paper investigates how soft vibrational modes in magnetic molecules influence low-temperature electronic transport, revealing anomalous behaviors and weak gate voltage dependence of the Kondo temperature, aligning with recent experimental findings.

Contribution

It introduces a model for electronic transport through magnetic molecules with soft vibrational modes, highlighting the impact on Kondo physics and transport anomalies.

Findings

Weak gate voltage dependence of the Kondo temperature

Transport anomalies due to soft vibrational modes

Agreement with recent experimental data

Abstract

The low-temperature transport properties of a molecule are studied in the field-effect transitor geometry. The molecule has an internal mechanical mode that modulates its electronic levels and renormalizes both the interactions and the coupling to the electrodes. For a soft mechanical mode the spin fluctuations in the molecule are dominated by the bare couplings while the valence changes are determined by the dressed energies. In this case, the transport properties present an anomalous behavior and the Kondo temperature has a weak gate voltage dependence. These observations are in agreement with recent experimental data.