Spin transport in higher n-acene molecules

Abstract

We investigate the spin transport properties of molecules belonging to the acenes series by using density functional theory combined with the non-equilibrium Green's function approach to electronic transport. While short acenes are found to be non-magnetic, molecules comprising more than nine acene rings have a spin-polarized ground state. In their gas phase these have a singlet total spin configuration, since the two unpaired electrons occupying the doubly degenerate highest molecular orbital are antiferromagnetically coupled to each other. Such an orbital degeneracy is however lifted once the molecule is attached asymmetrically to Au electrodes via thiol linkers, leading to a fractional magnetic moment. In this situation the system Au/n-acene/Au can act as an efficient spin-filter with interesting applications in the emerging field of organic spintronics.

13 pages,9 figures

References in corpus (5)

• Renormalization of Molecular Electronic Levels at Metal-Molecule Interfaces
• Unravelling the role of the interface for spin injection into organic semiconductors
• The radical character of the acenes: A density matrix renormalization group study
• Electronic Ground State of Higher Acenes
• Finite-bias electronic transport of molecules in water solution

Cited by in corpus (1)

• Fate of the open-shell singlet ground state in the experimentally accessible acenes: a quantum Monte Carlo study