TY  - CONF
AU  - Schäpers, Thomas
TI  - Phase-coherent transport in topological insulator nanoribbon-based structures
M1  - FZJ-2019-02895
PY  - 2019
AB  - Three-dimensional topological insulators have been subject of increased interest in the past few years due to their robust topologically protected surface states enclosing an insulating bulk. Especially the spin-momentum locking of these surface states makes this novel material class very attractive for spintronic applications. However, often the transport in the surface states is masked by a pronounced bulk conductance contribution owing to a relatively large background doping. By preparing topological insulator nanoribbons a more favorable surface-to-volume ratio can be achieved. In addition, these nanostructures allow to study confinement related carrier transport. Our topological insulator Bi2Te3 and Sb2Te3-based nanostructures were fabricated by selective-area molecular beam epitaxy using a SiO2/Si3N4-masked Si (111) substrate. We performed low temperature magnetotransport measurements on the nanoribbons, in order to investigate phase-coherent phenomena. Furthermore, nanoribbons were covered in-situ with superconducting electrodes to form topological Josephson junctions. Here, a clear Josephson supercurrent was observed. Measurements under microwave irradiation revealed a series of Shapiro steps. The observed missing of the first step indicates the presence of Majorana states.
T2  - Symposium on Quantum and Nanoelectronic Devices
CY  - 29 Apr 2019 - 29 Apr 2019, Lund (Sweden)
Y2  - 29 Apr 2019 - 29 Apr 2019
M2  - Lund, Sweden
LB  - PUB:(DE-HGF)31
UR  - https://juser.fz-juelich.de/record/862633
ER  -