Influence of Majorana bound states on conductance characteristics in a T-shaped quantum dot molecule

Abstract

Quantum dots (QDs) in contact with normal-metal and superconducting leads exhibit remarkable electron transmission features. The coupling of Majorana bound states (MBSs) has made them a promising platform for the development of mesoscopic structures. To elaborate on the highly efficient mesoscopic mode, the Andreev conductance in a T-shaped QD molecule coupled with MBSs is theoretically addressed. As the QD-MBS coupling strength λ is focused with respect to the QD energy level ${\epsilon }_1={\epsilon }_2=0$ in a T-shaped QD molecule, the conductance peak at ${\epsilon }_F=0$ rises up to 0.5$e^2/h$. At ${\epsilon }_1={\epsilon }_2=0$, the bonding and antibonding states are captured in the conductance lines as suitable QD-MBS or MBS-MBS coupling ${\epsilon }_M$ survives. Furthermore, for the asymmetric QD-lead coupling case, changing ${\epsilon }_M$ not only induces a transition in zero bias peaks but also suppresses the conductance curve in a low critical bias regime. The present findings can deepen the understanding of the influence of MBSs on electron transport features, highlighting the potential of T-shaped QD molecules coupled with MBSs for additional development and applications in mini-sized devices.