Spin transport of electrons through quantum wires with spatially-modulated strength of the Rashba spin-orbit interaction

摘要

We study ballistic transport of spin-polarized electrons through quantumwires in which the strength of the Rashba spin-orbit interaction (SOI) isspatially modulated. Subband mixing, due to SOI, between the two lowestsubbands is taken into account. Simplified approximate expressions for thetransmission are obtained for electron energies close to the bottom of thefirst subband and near the value for which anticrossing of the two lowestsubbands occurs. In structures with periodically varied SOI strength, {\itsquare-wave} modulation on the spin transmission is found when only one subbandis occupied and its possible application to the spin transistor is discussed.When two subbands are occupied the transmission is strongly affected by theexistence of SOI interfaces as well as by the subband mixing.