Local electronic structure of topological semi-metals and insulators

• Applicant: Dr. Anna Strózecka
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2010 to 2013
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 167120867

A new topological phase of matter with intriguing electronic properties has been recently discovered in metal alloys with strong spin-orbit coupling. These materials exhibit robust metallic surface electronic bands and, in case of bulk insulators, intriguing spin-transport properties. In this research project we plan to investigate the characteristic properties of a topological phase of matter at the local scale using low temperature scanning tunnelling microscopy. We will study two extreme semi-metallic systems with different topological order, bismuth and antimony, as well as an epitaxial mixture of them BiSb and BiSe, which are known to be a topological insulators. We aim to determine how the topological order affects the scattering mechanisms of the characteristic spin-polarized bands, by comparing electron interference patterns around surface defects. Our immediate goal is to confirm several predictions regarding the behaviour of the new topological phase of matter under magnetic fields and when doped with magnetic impurities. Our study will provide an experimental insight into electron dynamics in spin polarized surface states with different topological order parameter.

• DFG Programme: Research Grants
• Participating Person: Professor Dr. Jose Ignacio Pascual