Atomically thin layers of the semimetal tungsten ditelluride conduct electricity losslessly along narrow, one-dimensional channels at the crystal edges. The material is therefore a second-order topological insulator. By obtaining experimental proof of this behavior, physicists from the University of Basel have expanded the pool of candidate materials for topological superconductivity. The findings have been published in the journal Nano Letters.
Topological insulators represent a key area of research because they could potentially be used as superconductors in the electronics of the future. Materials of this kind behave like insulators on the inside, whereas their surfaces have metallic properties and conduct electricity. A three-dimensional crystal of a topological insulator therefore conducts electricity on its surface, while no current can flow inside. Moreover, due to quantum mechanics, the conductivity on the surface is almost lossless – the electricity is conducted over long distances without heat generation.
In addition to these materials, there is another class known as second-order topological insulators. These three-dimensional crystals have conductive, one-dimensional channels running along only certain crystal edges. Materials of this kind are particularly well suited to potential applications in quantum computing.
Source: “Lossless conduction at the edges”, University of Basel