Abstract
Klaus Richter Tuesday, 15:10 - 15:40
Magneto-transport in 3D topological insulator nanowires
We investigate the transport characteristics of 3D topological insulator (3D TI) nanowires in external electric and magnetic fields. The wires host topologically non-trivial surface states wrapped around an insulating bulk and are modelled by bulk and surface effective Hamiltonians. A magnetic field along the wire axis leads to Aharonov-Bohm oscillations of the conductance. Such oscillations have been observed in various systems and signal surface transport, though alone cannot prove its topological nature. Furthermore, it is not known how they are affected by the wire specific geometry that is never perfectly tubular as assumed in theoretical models.
We thus focus on two major aspects: (i) A theoretical study of magneto-conductance through shaped (tapered, curved) 3D TI nanowires. In particular, a non-constant radius along the wire direction gives rise to a spatial variation of the enclosed magnetic flux, implying novel quantum transport phenomena; (ii) an accurate modelling of surface transport in gated, strained HgTe nanowires in view of corresponding experiments of the Weiss group, Uni Regensburg.