Topological insulators represent a novel class of materials which are truly insulating in the bulk but metallic at the surface. We have recently been successful to prepare high quality thin films of the topological insulator Bi2Te3 by molecular beam epitaxy (MBE) in our unique ultra-high vacuum (UHV) system which allows also for an all in-situ sample characterization. The UHV facility consists of an MBE chamber equipped with electron diffraction techniques (RHEED and LEED) for the structural characterization, an analysis chamber for photoelectron spectroscopy (XPS, ARPES) to determine the bulk and surface electronic structure, and a setup for temperature-dependent resistivity measurements.
The goal of this project is now to find suitable superconducting materials to deposit on top of these Bi2Te3 films to study the transport properties of the topological insulator-superconductor heterostructure. By performing a systematic investigation of different layer thicknesses a better understanding of the superconducting proximity effects shall be achieved.
Contact:
Dr. Simone Altendorf,
Max Planck Institute for Chemical Physics of Solids, Dresden, Germany.
Email: Simone.Altendorf@cpfs.mpg.de
![Left: Ultra-high vacuum system for preparation and characterization of thin films. Right: Angle resolved x-ray photoemission spectra of a Bi2Te3 thin film. The spectra show the electronic structure of the material for different directions (angles). [K. Hoefer et al., PNAS 111 (42), (2014)]](/6286091/original-1518447301.jpg?t=eyJ3aWR0aCI6ODQ4LCJmaWxlX2V4dGVuc2lvbiI6ImpwZyIsIm9ial9pZCI6NjI4NjA5MX0%3D--98d06f758af8271939938a61082e2f06eefdd15a "Left: Ultra-high vacuum system for preparation and characterization of thin films. Right: Angle resolved x-ray photoemission spectra of a Bi2Te3 thin film. The spectra show the electronic structure of the material for different directions (angles). [K. Hoefer et al., PNAS 111 (42), (2014)]")
![Left: Ultra-high vacuum system for preparation and characterization of thin films. Right: Angle resolved x-ray photoemission spectra of a Bi2Te3 thin film. The spectra show the electronic structure of the material for different directions (angles). [K. Hoefer et al., PNAS 111 (42), (2014)]](/6286091/original-1518447301.jpg?t=eyJ3aWR0aCI6MjQ2LCJvYmpfaWQiOjYyODYwOTF9--d076cfe2055c08be7d5b7299c1e2c92dbdfc1b71)
Left: Ultra-high vacuum system for preparation and characterization of thin films. Right: Angle resolved x-ray photoemission spectra of a Bi2Te3 thin film. The spectra show the electronic structure of the material for different directions (angles). [K. Hoefer et al., PNAS 111 (42), (2014)]