RC-coupled ferromagnetic single-electron transistors

We study quantitatively the operation of ferromagnetic single-electron transistors coupled to the controlling gate potential by the gate resistance and gate capacitance in series. In this type of the device, several metastable charge states are possible within the range of Coulomb blockade. The enhancement and hysteresis of tunnel magnetoresistance on the drain and gate voltages are predicted. The inelastic macroscopic quantum tunneling of charge and the existence of several charge states play an important role in the unique behavior of tunnel magnetoresistance. This implies that RC-coupled ferromagnetic single-electron transistors have a functionality as novel magnetoresistive nanostructure devices. (C) 2003 American Institute of Physics.