Quantum sensing with highly transparent Al-InAs planar Josephson junctions

Josephson junctions of superconducting epitaxial aluminum on quantum wells of semiconducting indium arsenide with large spin-orbit coupling have been proposed to exhibit topological superconductivity. The topological state is stabilized at a phase difference of π where the current-phase relation of a transparent junction becomes highly sensitive to changes in magnetic flux. We fabricate planar junctions embedded in a SQUID geometry, enabling phase-sensitive measurements. We study the current-phase relation and tunneling spectrum of the junction as a function of in-plane Zeeman field and gate voltage. We further explore the integration of remote flux lines to bias the junction to a phase difference of π, where the magnetometric sensitivity of the device is significantly enhanced.