Rashba spin splitting in different quantum channels

Rashba precession of spins moving along a one-subband quantum channel is calculated. The quantitative influence of unoccupied higher subbands depends on the shape of the transversal confinement and can be accounted for perturbatively. Coulomb interactions are included within the Tomonaga–Luttinger model with spin-orbit coupling incorporated. Increasing interaction strength at decreasing carrier density is found to {\sl enhance} spin precession.