Nature creates electrons with two values of the spin projection quantum number. In certain applications, it is important to filter electrons with one spin projection from the rest. Such filtering is not trivial, since spin-dependent interactions are often weak, and cannot lead to any substantial effect. Here we propose an efficient spin filter based upon scattering from a two-dimensional crystal, which is made of aligned point magnets. The polarization of the outgoing electron flux is controlled by the crystal, and reaches maximum at specific values of the parameters. In our scheme, polarization increase is accompanied by higher reflectivity of the crystal. High transmission is feasible in scattering from a quantum cavity made of two crystals. Our findings can be used for studies of low-energy spin-dependent scattering from two-dimensional ordered structures made of magnetic atoms or aligned chiral molecules.

自然产生具有两个自旋投影量子数值的电子。在某些应用中，重要的是从其余部分以一个自旋投影来过滤电子。由于自旋相关的相互作用通常较弱，并且不能导致任何实质性的影响，因此这种过滤并非无关紧要。在这里，我们提出了一种有效的自旋滤波器，它基于二维晶体的散射，该二维晶体由对准的点磁体组成。输出电子通量的极化由晶体控制，并在参数的特定值达到最大值。在我们的方案中，偏振的增加伴随着晶体更高的反射率。在由两个晶体构成的量子腔中进行散射时，高透射率是可行的。