Topological Josephson junctions based on InGaAs quantum wells

Majorana phases emerge as quantized plateaus in the magnetoconductance of the hybrid junctions based on two-dimensional electron gases (2DEG) under fully out-of-plane magnetic fields [1,2]. The large transverse Rashba spin-orbit interaction in 2DEG, together with a strong magneto-orbital effect, yield topological phase transitions to nontrivial phases hosting Majorana modes. Such Majorana modes are formed at the ends of 2DEG-based wires with a hybrid superconductor-semiconductor integrity. Here, we report on the experimental observation of such topological phases in Josephson junctions, based on In0.75Ga0.25As 2DEG, by sweeping out-of-plane magnetic fields of as small as B(mT) < 100 and probing the conductance to highlight the characteristic quantized magnetoconductance plateaus.
[1] Kaveh Delfanazari, et al. https://arxiv.org/abs/2007.02057
[2] Lorenc Serra and Kaveh Delfanazari, https://journals.aps.org/prb/abstract/10.1103/PhysRevB.101.115409