Andreev reflections and magnetotransport in 2D Josephson junctions

Abstract

In this paper, the subharmonic energy gap structures (SGS) and induced superconductivity, due to multiple Andreev reflections, in indium gallium arsenide (In0.75Ga0.25As) two-dimensional electron gas (2DEG) are discussed at different temperatures and magnetic fields. Strong suppression of both SGS and induced gap are observed as a function of temperature and magnetic field. The differential conductance of the Josephson junctions (JJs) as a function of external in-plane magnetic fields shows an asymmetric response to positive and negative magnetic field sweeps with a conductance maximum at close to zero. Our approach to quantum transport studies of the ballistic 2D JJs may open a new road towards scalable and integrated quantum processing and help pave the way for the development of topological circuits for the realization of the next generation of quantum processors.