Superconducting Tunneling Spectroscopy of InSb Nanowires

Semiconducting InSb nanowires that are proximity-coupled to s-wave superconductors are strong candidates to host Majorana zero modes, which are non-abelian anyonic quasiparticles that may be "braided" in a two-dimensional system to serve as quantum logic gates. This motivates an in-depth study of the quasiparticle transport inside the nanowire. First, we present a technique to construct minimally invasive superconducting tunnel probes on the 1.2 micron-long nanowire devices, which show Fabry-Perot signatures, implying coherent electron transport. We then discuss the gate- and bias-dependence of tunneling measurements, which demonstrate the functionality of the tunnel probes on the nanowires. Finally, we demonstrate non-equilibrium tunneling spectroscopy measurements, which suggest that strong electron-electron interactions characterize the quasiparticle transport within the nanowires.