# Majorana bound states in topological insulators and nanowires

Schrade, Constantin. Majorana bound states in topological insulators and nanowires. 2017, Doctoral Thesis, University of Basel, Faculty of Science.

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Official URL: http://edoc.unibas.ch/diss/DissB_12318

In the first part of this thesis, we introduce two new platforms for generating Majorana bound states based on proximity-induced Pi Josephson junctions in topological insulators and crossed-Andreev pairing between semiconductor Rashba nanowires. Unlike the current experimental setups, the proposed schemes require either low magnetic fields or no magnetic fields at all. The latter characteristic constitutes a compelling improvement over current experimental setups for two reasons: (1) The detrimental effects of the magnetic fields on the superconductivity are either reduced or completely avoided. (2) In current experimental schemes the proximity-induced superconducting gap, which assures the topological protection of the Majorana qubits, is well-defined only at low magnetic fields (hard gap"). At strong magnetic fields, a finite subgap conductance arises (soft gap") and destroys the topological protection . Hence, with regards to future experiments on quantum information procession with Majorana bound states, a setup operated at lower magnetic field is highly desirable.