Distinguishing Majorana and Andreev bound states in a topological superconducting nanowire with a potential barrier

Abstract

We propose a scheme to distinguish the Majorana bound states (MBSs) and the trivial Andreev bound states (ABSs) in a topological superconducting nanowire by applying a sharp local potential barrier on one part of the wire. The position and strength of the local potential barrier could be modulated by a gate voltage applied to the nanowire. It is found that a new pair of MBSs appear at both sides of the potential in the presence of the local potential barrier, as a manifestation of the topological nature. Differently, the local potential barrier does not induce extra ABSs. Such a difference can be traced back to the evolution of the conductance spectrum with the Zeeman field or the local potential strength. When modulating the local potential strength, the zero-bias conductance peak induced by MBSs can be split into two-, three-, or four-peak structures, while the zero-bias peak by ABSs is only split into two-peak form.