Magnetotransport in 3D Topological Insulator Nanowires
In recent years, the research field of topological insulators (TIs) has grown extremely fast due to its potential to produce revolutionary applications in electronics, spintronics, and quantum computation (to name just a few). Three-dimensional TIs (3DTIs) host massless Dirac-like surface states wrapped around an insulating bulk. The special attributes of these topologically protected states are not only interesting for applications, but also for studying fundamental aspects of physics, such as the Klein paradox.
This dissertation deals with the transport properties of 3DTI nanowires in the presence of external electric and magnetic fields, using numerical simulations based on effective surface Dirac Hamiltonians. In the first part, a joint experimental and theoretical effort is presented, which reveals the Dirac-like nature of the surface states on HgTe nanowires. The second part is devoted to nanowires with a varying cross section along their axis. Such curved nanowires grant access to a wealth of intriguing quantum transport phenomena and may serve as building blocks for new types of Dirac electron optic setups.