Around 2010 it became clear that semiconductor nanowire devices cannot be used just for the realization of spin qubits but also for the creation of so called topological qubits [1-3]. Since then several groups started working on semiconductor nanowires with strong spin orbit coupling in order to realize Majorana fermions in solid state devices. Experimental results showing a zero bias peak  and an 2e- to e-periodic change in the peak spacing of a Coulomb island  have been reported supporting the existence of Majorana fermions. However, in order reach the topological regime high magnetic fields are needed which can lead to a soft superconducting gap.
Recent theoretical works have suggested experimental setups which would relax the conditions imposed for the magnetic field strength [6,7]. These proposal include on the one hand parallel nanowires in which the electron-electron interactions open up the gap at k equal to zero  or nanowires fully covered with an Al shell for which the magnetic flux plays the role of the Zeeman field .
In our group we study hybrid superconductor-semiconductor devices based on proximitized InAs nanowires provided by the Microsoft Quantum Materials Lab .
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