# Topological insulator nanowires

Jens Bardarson, MPIPKS Dresden

17.07.2015 at 09:00

In this talk I will review the physics of topological insulator nanowires, both in the normal and superconducting state. The normal state transport properties are characterized by the interplay of the following phenomena: the surface Dirac fermions acquire a nontrivial Berry phase from spin rotation when circling the wire that opens up a gap in the spectrum; this gap can, through the Aharonov Bohm effect, be closed by a magnetic flux parallel to the wire, in which case a perfectly transmitted mode, protected by time reversal symmetry, emerges. When the wire is

made superconducting through a proximity effect, the perfectly transmitted mode turns into a Kramers pair of Majorana modes. Alternatively, one dimensional chiral modes can be induced by a magnetic field perpendicular to the wire—they are essentially edge states of quantum Hall insulators in the absence of a physical edge. When these chiral modes are combined with the Majorana modes, topological insulator nanowires realize a Majorana interferometer.

A 449 - Theresienstr. 37