Interferometric resonance signatures of Majorana bound states

Abstract

We calculate the current noise power spectrum in a nanoscopic interferometer consisting of a Majorana bound state (MBS) and a localized spin. We show that for large voltage (though less than the superconducting gap) several strong resonance peaks appear at frequencies that depend on the Zeeman splitting of the localized spin and on its tunneling to the localized spin. We also evaluate the differential conductance and find the unitary limit peak $2e^2/h$ at zero voltage as well as peaks at voltages corresponding to the resonances. We propose that detection of the resonances and related peaks in the differential conductance provide a strong support for the presence of an MBS.