Electron Double Refraction in Hybrid Systems with Rashba Spin-Orbit Coupling

We study the scattering of an electron in a definite state of spin at an interface of an hybrid system with a Rashba spin-orbit coupling on one side. Out of the normal incidence the double refraction phenomenon appears, with one or two limit angles for the total reflection. We show that this double refraction gives rise to a spin-dependent conductance of a Quantum Point Contact separating a ferromagnet and a two dimensional electron gas. The birefringence allows the spin filtering with a single interface.