Demonstrating a weak topological insulator in bismuth iodide

Topological insulators are one of the most exciting discoveries of the 21st century. They can be simply described as materials that conduct electricity on their surface or edge, but are insulating in their interior bulk. Their conductive properties are based on spin, a quantum mechanical property, and this suppresses the normal scattering of electrons off impurities in the material, or other electrons, and the amount of energy that is consequently lost to heat. In contrast to superconductors, to...