Local and Non-local Microwave Impedance of a Three-Terminal Hybrid Device

TL;DR

This paper introduces a microwave impedance measurement technique for superconductor-semiconductor hybrid nanowire devices with three terminals, enabling rapid, frequency-dependent analysis of local and non-local responses to distinguish Majorana modes from trivial states.

Contribution

It presents a novel microwave transmission line resonator method to measure complex scattering parameters of 3T devices across a broad frequency range, aiding in topological state identification.

Findings

Effective measurement of local and non-local responses.

Potential to differentiate Majorana zero modes from trivial states.

Rapid acquisition of complex S-parameters over 0.3-7 GHz.

Abstract

We report microwave impedance measurements of a superconductor-semiconductor hybrid nanowire device with three terminals (3T). Our technique makes use of transmission line resonators to acquire the nine complex scattering matrix parameters (S-parameters) of the device on fast timescales and across a spectrum of frequencies spanning 0.3 - 7 GHz. Via comparison with dc-transport measurements, we examine the utility of this technique for probing the local and non-local response of 3T devices where capacitive and inductive contributions can play a role. Such measurements require careful interpretation but may be of use in discerning true Majorana zero modes from trivial states arising from disorder.