Topological insulators represent a new state of quantum matter recently discovered with insulating bulk but conducting surface states formed by an odd number of Dirac fermions. In this Letter, we report our recent progress on the study of electronic structures of ex-situ grown topological insulator thin films by angle resolved photoemission spectroscopy (ARPES). We successfully obtained the topological band structures of molecular beam epitaxial HgTe and vapor–solid grown Bi2Te3 thin films after proper surface cleaning procedures. This new development will not only enable us to study more topological insulators that cannot be measured by conventional in-situ ARPES technique (e.g. by cleaving or growing samples in-situ), but also open the door to directly characterize the electronic properties of topological insulators used in functional devices.
文章作为封面，发表在physica status solidi-Rapid Research Letters 7, 130 (2013)