Signatures of Majorana bound state in an Aharonov-Bohm interferometer embedded with quantum dot

Abstract

Abstract We consider a ring geometry with a quantum dot (QD) embedded in one of its arms, which is coupled symmetrically to two normal leads and threaded by Aharonov-Bohm (AB) flux φ. The QD is coupled to a topological nanowire. Using scattering matrix method, the differential conductance and current cross correlation are investigated. By varying the external magnetic field strength and the coupling strength between the QD and Majorana bound state (MBS), the zero-bias conductance peak (ZBCP) will split and oscillate due to the overlapping of the two MBSs. Due to the sum rule in a pair of well-separated MBSs, the total differential conductance at zero bias voltage is quantized to 2e2/h. The total differential conductance and the current cross correlation show the periodicity of π with zero QD energy level and 2π with nonzero QD energy level.