Zeeman and spin-orbit effects in the Andreev spectra of nanowire junctions

Abstract

Microwave spectroscopy of a Josephson junction is a useful tool to directly measure the properties of Andreev bound states. Recently, this method has been successfully applied to junctions defined in proximitized InAs/Al nanowires whose realization is aimed at the study and use of Majorana zero modes. In these nanowires, Andreev bound states are sensitive to the interplay of spin-orbit coupling and applied magnetic field. Our theory investigates the evolution of the Andreev levels and of the associated microwave spectrum upon application and increase of magnetic field. The authors find that a drastic change in the spectrum occurs once the magnetic field is strong enough to affect the ground-state parity, which can happen before the topological transition. Besides explaining existing experimental data, the presented theory provides guidance for future experiments, involving the spectroscopic observation of the effects associated with Majorana zero modes.

Locations

• Physical review. B./Physical review. B - View - PDF
• arXiv (Cornell University) - View - PDF
• DataCite API - View