Giant magnetocurrent exceeding 3400% in magnetic tunnel transistors with spin-valve base layers

We report large magnetic field sensitivities of the collector current in a three-terminal magnetic tunnel transistor device with spin-valve metallic base layers. Giant magnetocurrents exceeding 3400% result from strong spin-dependent filtering of electrons traversing perpendicular to the spin-valve layers at energies well above the Fermi energy. The output current of the device can readily be tuned into the microampere regime by increasing the bias voltage across the tunnel barrier. With its giant magnetocurrent and reasonable output current, the magnetic tunnel transistor is a promising candidate for future magnetoelectronic devices. (C) 2003 American Institute of Physics.