Weyl Semimetal Path to Valley Filtering in Graphene

We propose a device in which sheet of graphene is coupled to Weyl semimetal, allowing for the physical access study tunneling from two- three-dimensional massless Dirac fermions. Because reconstructed band structure, we find that this acts as robust valley filter electrons sheet. show that, by appropriate alignment, semimetal draws away current one two valleys, while other pass unimpeded. In contrast proposed filters, mechanism our occurs bulk sheet, obviating need carefully shaped edges or dimensions.