Spin-filter device based on the Rashba effect using a nonmagnetic resonant tunneling diode.

TLDR: Detailed calculations using the InAlAs/InGaAs material system reveal that a splitting of a peak should be observed in the I-V curve of this device as a result of the spin-filtering effect.

Abstract: We propose an electronic spin-filter device that uses a nonmagnetic triple barrier resonant tunneling diode (TB-RTD). This device combines the spin-split resonant tunneling levels induced by the Rashba spin-orbit interaction and the spin blockade phenomena between two regions separated by the middle barrier in the TB-RTD. Detailed calculations using the InAlAs/InGaAs material system reveal that a splitting of a peak should be observed in the I-V curve of this device as a result of the spin-filtering effect. The filtering efficiency exceeds 99.9% at the peak positions in the I-V curve.

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TABLE I. Layer information for the proposed spin-filter device.

FIG. 1. (a) A schematic illustration of the proposed spin-filter device. The z axis is set vertically, pointing downward. The shaded areas denote the metal electrodes for the I-V measurement. (b),(c) Conduction band potential profiles for the proposed device to show how the matching of spin-dependent resonant tunneling levels is performed by controlling the emittercollector bias voltage VEC. The downward and upward arrows in region 1 denote the clockwise and counterclockwise spin states, respectively.

FIG. 2. The calculated spin-dependent tunneling currents as a function of the relative emitter-collector voltage DVEC. DVEC is defined as VEC 2 V 0 EC, where the proposed device structures retain a complete mirror symmetry about their middle barriers at VEC V 0 EC. (a), (b), and (c) are the results for device structures 1, 2, and 3 listed in Table I, respectively. Shown in the insets are the conduction band profiles for the corresponding device structures. The dashed and solid curves in the main graphs correspond to the tunnel currents for the clockwise # and counterclockwise " spins, respectively. For (c), these two curves overlap.