Alternate spintronic analog of the electro-optic modulator

There is significant current interest in spintronic devices fashioned after a spin analog of the electro-optic modulator proposed by Datta and Das [Appl. Phys. Lett. 56, 665 (1990)]. In their modulator, the “modulation” of the spin-polarized current is carried out by tuning the Rashba spin-orbit interaction with a gate voltage. Here, we propose an analogous modulator where the modulation is carried out by tuning the Dresselhaus spin-orbit interaction instead, using a split gate. Additionally, the magnetization of the source and drain contacts in our device is transverse to the channel, whereas in the Datta-Das device, it is along the channel. Therefore, in the present modulator, there is no magnetic field in the channel unlike in the case of the Datta-Das modulator. This can considerably enhance modulator performance.