Thin films based on topological Heusler materials

• Antragstellerinnen / Antragsteller: Dr. Stanislav Chadov; Professorin Dr. Claudia Felser, seit 11/2015; Professor Dr. Günter Reiss
• Fachliche Zuordnung: Experimentelle Physik der kondensierten Materie
• Förderung: Förderung von 2013 bis 2019
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 237534161

The long term goal of our combined proposal is to bring the developing research field of topological insulators closer to the real-life applications by producing the compounds, which can be applied in spintronics engineering. This goal implies a three-level collaboration between theory/characterization of suitable materials, growing thin films with optimized transport properties, and finally producing the combined devices. Our basic material source will be the family of cubic semiconducting Heusler compounds in which the first topologically-nontrivial systems were already identified. The Heusler family is one of the most studied diverse materials classes with many well-understood properties and long history in spintronics applications. The ab-initio analysis will be applied to select the suitable candidates. Here, materials with optimized properties for further thin films production are in the center of the work. Special effort will be put on the effects of disorder which often occur in multicomponent systems. Finally, advanced calculations will be performed to obtain their spectral and transport properties within the realistic surface and hetero-structure setup. This information will be necessary to guide the experimental part of the project, i.e. a high-quality growth of the thin films and their optimization with respect to the most important criteria: the stabilization of the Dirac surface states at the Fermi energy, optimal doping (most of the Heusler semiconductors are intrinsically p-doped), low carrier density and high mobility.All project co-partners have long-term experience by working with Heusler materials in theory, growth of thin films and production of combined hetero-structures for devices such as tunnel junctions. Being efficiently combined together this guarantees the success of our ambitious goal of developing new compounds for topological insulators, the realization in thin films and devices.

• DFG-Verfahren: Schwerpunktprogramme
• Teilprojekt zu: SPP 1666: Topologische Isolatoren: Materialien - grundlegende Eigenschaften - Strukturen für Bauelemente
• Ehemaliger Antragsteller: Dr. Daniel Ebke, bis 11/2015