Tunneling transport through multi-quantum-dot with Majorana bound states

Abstract

We have studied tunneling transport properties through multi-quantum-dot coupled to Majorana bound states (MBSs), in which only one quantum dot is connected with two normal leads. When the MBSs are sandwiched between two quantum dots (dot-MBSs-dot), the signature of Majorana fermions; namely, that the conductance is e2/h at zero fermion energy, is robust against the coupling (ϵM) between the two Majorana bound states as well as the coupling between the MBSs and the quantum dots which, in the dot-MBSs structure, will change even with a very small value of ϵM. The model that the Majorana bound states are coupled with one of a series of connected quantum dots (three connected quantum dots coupled with MBSs, e.g., dot-dot-dot-MBSs) is also investigated. Unlike the resonant condition for quantum dots structure with zero MBSs, if the MBSs couple with an even number of quantum dots, the conductance at zero Fermion energy is 2e2/h. On the other hand, in case of an odd number of quantum dots, it is e2/h.