Gate-induced switching in single-molecule magnet MnIIICuII

Gate voltage effect on electronic transport through the smallest single-molecule magnet (SMM) MnCu [(MnCuCl)-Cu-III-Cl-II(5-Br-sap)(2)(MeOH)] sandwiched between Au(100) electrodes is investigated by spin-polarized density functional theory calculations combined with the Keldysh nonequilibrium Green's technique. Our study demonstrates that a certain gate voltage can induce a switching of the conductance in the equilibrium state. Under a finite bias voltage, negative differential resistance is observed in this system and can be modulated by tuning the gate voltage. More interestingly, current rectification can be achieved at a certain negative gate voltage. These effects can be understood by the responses of the benzene rings and the magnetic core to an external electrical field. (C) 2011 American Institute of Physics. [doi:10.1063/1.3610448]