Aharonov-Bohm type periodic magnetoconductance oscillations in planar and ballistic superconductor-quantum wells Josephson junctions

It has been predicated that in the presence of a small perpendicular magnetic field, the magntoconductance oscillations (MCO) can be observed in planar and simply connected superconductor-semiconductor (S-Sm) junctions due to the interference effect of the Andreev reflected quasiparticles, interplay between quasiparticle cyclotron motion and the phase shift by the magnetic field. The MCO was found to be analogous to the Aharonov-Bohm type interference effect in a small ring [1,2]. Here, the first experimental observation of periodic MCO in planar and ballistic Josephson junctions at low prependicular magnetic fields B < ± 80 mT is reported [3]. The induced superconducting properties in In0.25Ga0.75As quantum wells is discussed [4-6]. Furthermore, it is shown that at zero source-drain voltage VSD bias, the differential conductance dI/dV of the junction drops in a step-like shape when B field is increased and as long as the quasiparticles are perfectly Andreev reflected at the Nb-In0.75Ga0.25As interfaces. A hysteresis that is accompanied by oscillations of dI/dV is observed when B field is in reverse sweep direction (see Fig.1). It is found that the conductance oscillations are strongly temperature dependent but independent of B field sweep rates [3].