First-principles study on electron transport through Mn(dmit)2 molecular junction depending on relative angle between ligands

Abstract

Density functional studies are performed for the conformational stability of a Mn(dmit)2 molecule and the transport properties of a Mn(dmit)2 molecular junction as functions of the relative angle θ between the two planar ligands. For an isolated Mn(dmit)2 molecule, the activation energy for the conformational transition from a coplanar conformation to a perpendicular conformation is 95 meV, whereas that for the reverse transition is only 8 meV. In the transport property calculations, spin-dependent properties are observed owing to the spin polarization that is derived from the Mn atom. In particular, for down-spin electron transport, nonmonotonic behavior with θ in the conductance spectrum is observed. It is confirmed that the d orbitals of the Mn atom play a key role in such behavior.