Researchers from NIST, the University of Maryland, and Seoul National University have developed a new method to control the energy levels at the surface of topological insulators using electric fields. These materials, which are insulators in their interior but conductive at their surfaces, could have important applications in electronics.
The researchers overcame a major challenge by creating special sample holders that allow them to grow pristine topological insulator films on pre-patterned electrodes without damaging the surface. By applying an electric field through the gating electrode, they can tune the doping of the top surfaces of the materials, varying their surface energy levels.
One particularly significant finding is that for ultra-thin antimony telluride (Sb2Te3) films, it may be possible to reversibly switch the material between being an ordinary insulator and a topological insulator, potentially enabling the “on and off” control of special properties at the material’s boundaries for electronic device applications.
Keywords: Topological, Insulators, Energy, Levels, Tuning
