Enhanced magneto-Coulomb effect in asymmetric ferromagnetic single electron transistors

Abstract

We investigate the magneto-Coulomb (MC) effect in a ferromagnetic single electron tunneling transistor (FM-SETT), with asymmetric junction resistances and FM electrodes. The MC effect enables the conductance of the FM-SETT by an applied magnetic B -field in addition to the usual gate-bias modulation. Under optimal biasing of the asymmetric FM-SETT near the sawtooth edge of its gate oscillation, the sensitivity γB =dIdB can be enhanced by a factor α, where α= R1 R2 denotes the junction resistance asymmetry. The enhanced B -field modulation is, however, susceptible to thermal smearing effects. Finally, an asymmetry in the magnetic properties of the FM leads results in a complex magnetoconductance response, with distinct conductance states. © 2009 American Institute of Physics.