We investigate single-molecule-magnet transistors (SMMTs) with ligands that support transport resonances. We find the lowest unoccupied molecular orbitals of Mn${}_{12}$-benzoate SMMs (with and without thiol or methyl-sulfide termination) to be on ligands, the highest occupied molecular orbitals being on the Mn${}_{12}$ magnetic core. We predict gate-controlled switching between Coulomb blockade and coherent resonant tunneling in SMMTs based on such SMMs, strong spin filtering by the SMM in both transport regimes, and that if such switching is observed, then the magnetic easy axis of the SMM is parallel to the direction of the current through the SMM.

• Received 25 June 2011

DOI:https://doi.org/10.1103/PhysRevB.84.180408