Properties of InAs- and silicon-based ballistic spin field-effect transistors

We investigate the transport properties of ballistic spin field-effect transistors. The transistor characteristics are examined for a broad range of parameters including the semiconductor channel length, the conduction band mismatch between the channel and the contacts, the strength of the spin-orbit interaction, and the magnetic field. We show that temperature exerts a significant influence on the device characteristics. For the InAs-based transistors a shorter channel is preferred for potential operations at room temperature. For the silicon-based transistors we demonstrate that the [100] fin orientation displays a stronger dependence of the magnetoresistanse on the strength of the spin-orbit interaction and is therefore best suited for practical realization of the silicon spin transistor.