Measurement of microwave impedance of proximitized nanowires using resonators*

We investigate the bulk properties of InAs nanowires proximitized by thin-film aluminium, which are a potential platform for topological quantum computing. We measure the frequency response of a quarter-wave coplanar wave guide resonator shunted by a hybrid Al-InAs nanowire as a function of gate voltage and axial magnetic field. From the detected shift in resonance frequency and quality factor, we extract the complex impedance of the nanowire. Our results show a monotonic dependence of the nanowire inductance and resistance on the gate voltage and an oscillating behaviour as a function of the axial magnetic field. This measurement approach complements existing characterization techniques and may facilitate the identification of the topological phase transition predicted for these hybrid structures.