Non-Magnetic Half-Metals

Abstract: Half-metals are a class of materials that are metallic only for one spin direction, and are essential for spintronics applications where one needs to read, write, store and transfer spin-data. This spin sensitivity appears to restrict them to be magnetic, and the known examples indeed are. The fabrication of real spintronic devices from such materials is often hampered, however, by stray magnetic fields, domain walls, short spin coherence times, scattering on magnetic atoms or magnetically active interfaces, and other characteristics that come along with the magnetism. The surfaces of topological insulators, or Dirac or Weyl semimetals, could be an alternative, but production of high-quality thin films without the presence of the bulk states at the Fermi level remains very challenging. Here we introduce non-magnetic half-metals and demonstrate that this state is realized in IrBiSe. Using angle-resolved photoemission spectroscopy and band structure calculations we find a record-high Dresselhaus spin-orbit splitting, fully spin-polarized remnant Fermi surfaces and a chiral 3D spin-texture, all with no magnetism present. Promising applications include using IrBiSe as a source of spin-polarized electrons, and lightly doped IrBiSe is expected to generate electric-field-controlled spin-polarized currents, free from back scattering, and could host triplet superconductivity.