Rashba spin–orbit effect on dwell time in graphene asymmetrical barrier

Abstract

We investigated the dwell time of electrons tunneling through an asymmetric barrier in monolayer graphene with the Rashba spin–orbit interaction (RSOI). The results show that the dwell time oscillates by increasing the barrier width, RSOI strength, and the bias voltage. In addition, when an external electric field is present, the spin polarization can be observed, whereas for the RSOI alone it is zero. Furthermore, it is found that electrons with different spin orientations will spend different times through the barrier. The difference of the dwell time between spin-up and spin-down electrons arises from the Rashba spin–orbit interaction. It can be concluded that Rashba spin–orbit effect can cause a natural spin filter mechanism in the time domain.