Influence of strong dot-lead couplings on the Majorana leakage effect

Abstract

By means of the scattering matrix and non-equilibrium Green function technique, the influence of dot-lead coupling on the Majorana leakage effect is theoretically studied. By calculating the conductance spectra and the local density of states, we find the conductance peaks coincide with the eigenlevels of the Majorana-dot hybrid system when the dot-lead coupling is relatively weak. With the increase of the dot-lead coupling, the Majorana leakage effect is manifested as the formation of one wide conductance peak at the zero-bias limit, whose widening is inversely proportional to the dot-lead coupling strength. When the left-right asymmetry is enhanced by strengthening the dot-lead coupling, the Majorana leakage effect shows the improvement of the zero-bias conductance peak. In the presence of superconducting proximity effect, the Majorana leakage effect is further modified in the case of left-right asymmetry of the dot-lead coupling. We believe that these results are helpful in further understanding the transport properties of the Majorana-dot hybrid systems.