Electron spin manipulation using semimagnetic resonant tunneling diodes

One major challenge for the development of spintronic devices is the control of the spin polarization of an electron current. We propose and demonstrate the use of a ${\mathrm{BeTe/Zn}}_{\text{1−x}}\mathrm{Se/BeTe}$ double barrier resonant tunneling diode for the injection of a spin-polarized electron current into GaAs and the manipulation of the spin orientation of the injected carriers via an external voltage. A spin polarization of up to 80% can be observed with a semimagnetic layer of only 3.5 nm thickness. By changing the resonance condition via the external voltage, the degree of spin polarization can be varied, though a complete spin switching has not yet been accomplished.