Parametric exploration of zero-energy modes in three-terminal InSb-Al nanowire devices

We systematically study three-terminal InSb-Al nanowire devices by using radio-frequency reflectometry. Tunneling spectroscopy measurements on both ends of the hybrid nanowires are performed while systematically varying the chemical potential, magnetic field and junction transparencies. Identifying the lowest-energy state allows for the construction of lowest- and zero-energy state diagrams, which show how the states evolve as a function of the aforementioned parameters. Importantly, comparing the diagrams taken for each end of the hybrids enables the identification of energy states which do not coexist simultaneously, ruling out significant amount of the parameter space as candidates for a topological phase. Furthermore, altering junction transparencies filters out zero-energy states sensitive to the local gate potential. Such a measurement strategy significantly reduces the time necessary to identify a potential topological phase and unambiguously reveals the trivial origin of the observed zero-bias peaks.