Perfect spin polarization in symmetric two-terminal mesoscopic rings

Spin-polarized transport through an Aharonov–Bohm (AB) semiconductor mesoscopic ring is investigated in the presence of both the Rashba spin–orbit interaction (RSOI) and the Dresselhaus spin–orbit interaction (DSOI). The ring symmetrically bridges two input and output electrodes. Based on tight-binding model and Green?s function formalism, we find that for AB fluxes other than integer or half-integer multiples of the flux quanta the ring acts as a spin selective device with unit efficiency only when the difference between strengths of RSOI and DSOI is nonzero and small. Results of this study can be used to design a nonmagnetic-material-based perfect spin filter.