Spin- and energy-dependent tunneling through a single molecule with intramolecular spatial resolution

TL;DR

This study uses low-temperature spin-polarized scanning tunneling microscopy and ab initio calculations to explore spin- and energy-dependent tunneling through a single organic molecule on a ferromagnetic surface, revealing spin-dependent effects despite a non-magnetic molecule.

Contribution

It demonstrates the spin-dependent tunneling through a non-magnetic molecule due to hybridized surface-molecule states, combining experimental and theoretical approaches.

Findings

Significant spin dependence of tunneling current in the molecule.

Hybridization of molecular orbitals with surface 3d states.

Non-magnetic molecule still shows spin-dependent tunneling effects.

Abstract

We investigate the spin- and energy dependent tunneling through a single organic molecule (CoPc) adsorbed on a ferromagnetic Fe thin film, spatially resolved by low-temperature spin-polarized scanning tunneling microscopy. Interestingly, the metal ion as well as the organic ligand show a significant spin-dependence of tunneling current flow. State-of-the-art ab initio calculations including also van-der-Waals interactions reveal a strong hybridization of molecular orbitals and surface 3d states. The molecule is anionic due to a transfer of one electron, resulting in a non-magnetic (S= 0) state. Nevertheless, tunneling through the molecule exhibits a pronounced spin-dependence due to spin-split molecule-surface hybrid states.