Controlled charge and spin currents in surface states of a toplogical insulator

• Applicant: Professor Dr. Hartmut Buhmann
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2013 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 237596888

This project addresses the fundamental properties of surface state transport in a topological insulator (TI). During the first part of this project the lithographic device preparation played the dominant role. Electrostatically clean surfaces are the prerequisite for the investigation of transport in TI systems. For the second part of this project samples of very high quality are available and dedicated lithographic processes will allow us to fabricated devices which show the undisturbed surface state transport. In this project we will continue to investigate the transport in helical edge channels of a 2D TI and here especially the stability against impurity, phonon and electron-electron scattering introduced by applying artificial scattering potential, external magnetic field and various temperatures. Furthermore, the availability of high quality 3D TI samples and fabrication technologies opens up the possibility to explore the fundamental transport properties of spin-momentum locked 2D Dirac electrons. Both parts are aiming at the feasibility of device concepts for spintronic applications, a goal which is aspired since long but where no significant progress has been achieved so far. This goal however has become a realistic prospect now within this project.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1666: Topological Insulators: Materials - Fundamental Properties - Devices
• Co-Investigator: Dr. Johannes Kleinlein