Spin polarization and conductance of the laterally asymmetric quantum point contact

We calculate conductance and polarization for the laterally asymmetric quantum point contact. We consider both Rashba coupling and spin-orbit interaction induced by asymmetric lateral confinement, without external magnetic field. We show that a conductance plateau may appear at 0.5G0(G0=2e2/h), without Rashba coupling and lateral spin-orbit interaction. For a spin-polarized injected current, the lateral spin-orbit interaction gives additional control of the conductance by varying the side gates potential. For unpolarized electrons, the spin polarization arises along all coordinate axes. There is a possibility of switching of spin polarization by the gates potential.