Electronic excitations of a single molecule contacted in a three-terminal configuration

TL;DR

This paper reports on low-temperature three-terminal transport experiments on a single molecule, revealing electronic excitations, Kondo effects, and charge-spin localization, modeled with a two-orbital approach.

Contribution

It introduces a simplified two-orbital model to explain charge and spin states in a three-terminal molecular device, advancing understanding of molecular electronic excitations.

Findings

Observation of zero and finite-bias Kondo effects

Charge and spin localization at molecule ends

Charge-dependent coupling to electrodes

Abstract

Low-temperature three-terminal transport measurements through a thiol end-capped Pi -conjugated molecule have been carried out. Electronic excitations, including zero and finite-bias Kondo-effects have been observed and studied as a function of magnetic field. Using a simplified two-orbital model we have accounted for the spin and the electronic configuration of the first four charge states of the molecule. The charge-dependent couplings to gate, source and drain electrodes suggest a scenario in which charges and spins are localized at the ends of the molecule, close to the electrodes.