Hg-Based Epitaxial Materials for Topological Insulators
Final rept. 1 Feb 2013-14 May 2014
UNIVERSIDAD AUTONOMA DE MADRID (SPAIN)
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Topological insulators TI stand as a new class of materials in which spin-orbit interaction produces topologically nontrivial insulating bulk electronic phases and conducting material boundaries. These boundary regions show complex spin textures and have properties that are unlike any other known 2D electronic systems with foreseen applications ranging from topological superconductors and spintronics to quantum computation. Recent trends in TI consist in searching for new candidate 2D materials like heavy element high Z magnetic TI. In particular, diluted magnetic semiconductors such as Hg1-xMxVI, where M is a transition metal e.g., Mn, Fe, Cr and VI is a Group VI element e.g., Te, Se, are of special interest due to their variable band-gap and excellent electronic-transport and optical properties. In this study, TI structures were made by sandwiching a thin layer of Hg-based material between CdZnTe substrates and cover layer of CdTe. Several geometries and compositions were produced with controllable topological structure using both vapor-phase epitaxy and liquid-phase epitaxy, along with associated microstructural characterization. Samples were provided to the Air Force Research Laboratory for investigation of properties.
- Solid State Physics