Spin Filtering in Multiple Scattering off Point Magnets.

Electron spin filters that produce spin-polarized currents of high intensity have important applications in different branches of physics. In this work, we propose an efficient spin filter based upon scattering off a two-dimensional crystal made of aligned point magnets. We demonstrate that such crystal greatly increases polarization for specific `magic' values of parameters. While polarization increase is accompanied by higher reflectivity of the crystal, higher output currents can be obtained in scattering off a quantum cavity made of two crystals. Besides being a spin filter, our setup gives some insight into collective scattering of electrons from aligned chiral molecules, and, thus, into the chiral induced spin selectivity effect.