Electron Transport Through a Molecular Junction Using a Multi-configurational Description

The importance of the electronic description of the junction electronic structure is investigated in quantum transport through molecular devices. Using an accurate wave-function-based description of the low-energy spectroscopy, transport through a 2-electron/2-molecular orbital prototype is evaluated. The contributions arising from the presence of competing singlet and triplet states in magnetic systems are analyzed. It is shown that the electronic conductivity provides a signature of the full multiplet energy spectrum, as well as of the multideterminant structure of wave-functions. We then inspected the current-potential characteristics as a function of the differential magnetization of the electrodes. From the wave-function description, a modulation of the magnetoresistance ratio is anticipated and both direct and inverse regimes are observed depending on the electronic structure of the junction.