Researchers from the Swiss Federal Institutes of Technology Lausanne, the Paul Scherrer Institute in Switzerland, and the Chinese Academy of Science have demonstrated, for the first time, that samarium hexaboride (SmB6) is a topological insulator. Topological insulators can be used to control electronic spin because they conduct electrons only across their surface but not through their interior. These materials can conduct spin polarized electrons across their surface with 100% efficiency while the interior acts as an insulator. However, topological insulators are still in the experimental phase. Unlike other topological insulators, SmB6’s insulating properties are based on the Kondo effect, which prevents the flow of electrons from being destroyed by irregularities in the material’s structure.The researchers have shown experimentally that SmB6 is the first topological Kondo insulator. In experiments, they illuminated samples of SmB6 with synchroton radiation, and the energy of the light was transferred to electrons in SmB6. The data collected during this experiment showed consistent agreement with the predictions for a topological insulator.
Source: EurekAlert
