Topological insulators – inline electron holography studies

Topological insulators are called a new state of matter. The bulk material shows insulating behavior whereas metallic conductivity is exhibited at the surface. We are investigating topological insulators, mainly Bi₂Se₃ and Bi₂Te₃, using various transmission electron microscopy techniques. In conventional transmission electron microscopy, the image contains information only of the electron wave’s amplitude and phase information is lost after image formation. Inline electron holography is used to determine the electrical properties of the topological insulator surfaces, knowledge of which allows the reconstruction of the exit wave function.